15-

I personally think that the M-Colours should be described.

ULTRAMARINE
RESEARCH
AND
MORE
COMPLETE
SUMMARY
AS TO

ULT-LEAD
PERMENENCE

An improvement in the book which I would like to see would be the result of a new research on ultramarine Blue (artifactual).

Is the first class ultraviolet made in US equal to that of Europe?

Who are the makers of Al ultraviolet in America?

Further research as to the mixability of ultramarine (art) with Lead?

There are plenty of brilliant and desirable colors which alone are permanent. The question rests almost wholly on the mixability of

a pigment with { lead
aluminum
iron.

Is the evidence ultramarine vs lead sufficient to exclude the lead from a lead pal, or lead from an ultraviolet pal?

Or is the negative influence negligible? That is: Is the possible injury to be accepted in lieu of no alternative.

THE
QUESTION OF
MIXABILITY

ULTRAMARINE
RESEARCH

Would it not be well to search other books if there are any that offer different evidence and inquire from Toch, poring him a set of questions which would force from him some sort of estimate or sum up.

AUTHORITIES
CONTRADICTIONS

(If you find all the "authorities" more or less contradicting themselves and it is perhaps necessary to pin them down to answering what you want them to answer)

(Continued on page 16 - back of page 1)

CLASSIFICATION OF PIGMENTS

(CHURCH, 249)

MINERAL PIGMENTS { NATURAL; as Ochre, Terre Verte, Ultramarine.
(ARTIFICIAL; as Aureolin, Viridian, Cobalt Blue

The Mineral Pigments are, as a rule, characterized by a much
higher degree of permanence than those of organic origin.

(ANIMAL; as Indian Yellow, Carmine, Sepia.
ORGANIC PIGMENTS { VEGETABLE; as Gamboge, Sap Green, Indigo.
(ARTIFICIAL; as Prussian Blue, Verdigris.

(Church p. 251 & 253) ELEMENTS
BLACKS: {
  IVORY BLACK
  CHARCOAL BLACK
  LAMP BLACK
  INDIAN INK
  GRAPHITE
  SILVER
  GOLD
  PLATINUM
  ALUMINIUM
}

BLACKS - All the Black pigments in ordinary use consist of
or contain the element Carbon, and are not subject
to change.

GRAPHITE - Is a form of Carbon and is unalterable and inert.

GOLD - Is not liable to chemical change.

SILVER - Tarnishes by combination with sulphur.

OXIDES

ZINC WHITE ZnO
GREEN OXIDE OF CHROMIUM Cr2O3
BURNT UMBER Oxides of Fe and Mn.
COBALT GREEN CoO, ZnO.
COBALT RED CoO, MgO
COBALT BLUE (Genuine) CoO, Al2O3
COERULEUM CoO, SnO2
RED LEAD PbO
VENETIAN RED
LIGHT RED
INDIAN RED
BURNT SIENNA
Chiefly Fe2O3

These have generally been prepared at a high temperature.

Are not easily amenable to chemical or physical change.

They are not liable to affect other pigments, being practically inert.

| SIGN | NAME | VALENCE |
| :--- | :--- | :--- |
| Zn | Zinc | 2 |
| O | Oxygen | 2 |
| Cr | Chromium | II, III, IV |
| Fe | Iron | II, III |
| Mn | Manganese | II, IV |
| Co | Cobalt | II |
| Mg | Magnesium | II |
| Al | Aluminium | III |
| Sn | Tin | II, IV |
| Pb | Lead | II, IV |

SULPHIDES

CADMIUM YELLOW Cds
KING'S YELLOW As2S3
REALGAR As2S2
VERMILION HgS
ULTRAMARINE
ARTIFICIAL ULTRAMARINE
GREEN ULTRAMARINE
RED ULTRAMARINE
-Contains Si, Al, Na, O, S.

Some of these may give up sulphur to the metallic bases of other pigments.

Thus **Cadmium Yellow** blackens Emerald Green, producing copper sulphide.

**Vermilion** is prone to a molecular change, whereby the red crystalline form passes, without chemical alteration into the black amorphous variety.

The members of this group sometimes contain free sulphur, or injurious sulphur compounds.

| SIGN | NAME | VALENCE |
|---|---|---|
| Dl | Cadmium | II |
| S | Sulphur | II, IV, VI |
| As | Arsenic | III, V |
| Hg | Mercury | I, II |
| Si | Silicon | IV |
| Al | Aluminum | III |
| Na | Sodium | I |
| O | Oxygen | II |
| S | Sulphur | II, IV, VI |

HYDRATES

YELLOW OCHRE `-----------------Fe₂O₃,nH₂O`

RAW SIENNA `-----------------`) ( Oxides and hydrates
}-{

RAW UMBER `----------------`) ( of Fe and Mn

EMERALD OXIDE OF CHROMIUM `-------Cr₂O₃, 2H₂O`

MOUNTAIN BLUE `-----------------CuH₂O₂`

The water present in these compounds exists in two states,
esential and hygroscopic.

Sometimes a part of the former may be lost, and a change of
hue occur in consequence, but the alteration is rare,
save in the pigments which owe their color to the pre-
sence of copper hydrate.

In the case of RAW UMBER, the water present acts rather in
aiding the oxygen of the air, under the influence of
sunlight, to oxidise some of the peaty or bituminous
matter sometimes present in this pigment.

| SIGN. | NAME | VALENCE |
| :--- | :--- | :--- |
| Fe---| Iron---| II, III |
| O---| Oxygen---| II |
| H---| Hydrogen---| I |
| Mn---| Manganese---| II, IV |
| Cr---| Chromium---| II, III, IV |
| Cu---| Copper---| I, II |

CHROMATES

BARYTA YELLOW &c.-----------------BaCrO₄

STRONTIA YELLOW -----------------SrCrO₄

CHROME YELLOW -----------------PbCrO₄

CHROME RED

CHROME RED -------------------Pb₂CrO₅

ZINC CHROMATE -----------------ZnCrO₄

This group consists of compounds rich in oxygen.

When in contact with some of the more alterable organic pigments (see "Inorganic Salts" page 7) the chromates occasionally ally loose oxygen.

On account of this they show a tendency to acquire a greenish or grayish hue, the result of the reduction of the red oxide of chromium to the green oxide.

This change is accompanied by a corresponding injury to the color of the organic pigment which has been involved in the reaction.

SIGN NAME VALENCE

Ba-----Barium----------II

Cr-----Chromium--II, III, IV

O-----Oxygen----------II

Sr-----Strontium-------II

Pb-----Lead----------II-IV

Zn-----Zinc----------II

VARIOUS INORGANIC SALTS

BARYTA WHITE BaSO₄
LEAD SULPHATE PbSO₄
AUREOLIN K₂Co₂¹²NO₂
NAPLES YELLOW Contains Pb, Sb, O
SCHWEINFURT GREEN Contains Cu, As, O
TUNGSTEN GREEN Chromium Tungstate
MANGANESE VIOLET )
NURBERG VIOLET ) Manganese metaphosphate

A number of miscellaneous compounds having no chemical relationship have been thrown into this group.

One, a sulphate, is insoluble and inalterable; (Baryta Wt.)

Another, potassium cobalti-nitrate is generally inert, but owing to its nitrous constituent, acts injuriously upon some organic pigments, notably on Indigo. (Aureolin)

The members of the group which contain Lead or Copper may darken in the presence of sulphuretted hydrogen and of some other sulphur compounds.

SIGN, NAME VALENCE

Ba---Barium---II
S---Sulphur--II, IV, VI
O---Oxygen---II
Pb---Lead---II, IV
K---Potassium---I
Co---Cobalt---II
N---Nitrogen---III, V
Sb---Antimony---III, V
Cu---Copper---I-II
As---Arsenic---III, IV

NOTE ON THE FOREGOING CLASSIFICATION

It should be noted that the members of each group, though presenting one or more characters in common, often exhibit certain chemical and physical differences of deportment.

Here is a list of the chief changes which they are capable of suffering, with illustrative examples:

<table><tr><td>MOLECULAR REARRANGEMENT</td><td>(VERMILION<br>CADMIUM SULPHIDE)</td></tr><tr><td>VOLATILIZATION</td><td>KING'S YELLOW</td></tr><tr><td>SUBSIDENCE</td><td>SMALT</td></tr><tr><td>SOLUTION</td><td>(STRONTIA YELLOW<br>(AUREOLIN))</td></tr><tr><td>FUSION</td><td>ASPHALT</td></tr><tr><td>OXIDATION</td><td>(CARMINE<br>(VANDYKE BROWN))</td></tr><tr><td>REDUCTION</td><td>(NAPLES YELLOW<br>(CHROMATES))</td></tr><tr><td>SULPHURATION</td><td>(WHITE LEAD<br>(EMERALD GREEN))</td></tr></table>

One of the chief lessons to be learned from this classification is this:

**EFFECT ON EACH OTHER OF MEMBERS OF EACH CLASS**

That the members of each class, as a general rule, exert no action on one another.

**This is explained easily:**

**EFFECT OF OXIDES ON OXIDES**

The oxides of the "Oxide Group" having already taken up the full compliment of oxygen which they can acquire under ordinary conditions, are not likely to be oxidized by admixture with other oxides of similar character.

**EFFECT OF SULPHIDES ON SULPHIDES**

In the same manner the sulphides of the "Sulphide Group" neither give sulphur to, nor receive it from the other sulphides, for all but one have been produced in the presence of excess of sulphur.

23

CHURCH'S CLASSIFIED PIGMENTS
FOR OIL PAINTING.

(Church's book 1901)

(Church, page 258)

<table><thead><tr><th>CLASS I</th><th>CLASS II</th><th>CLASS III</th></tr></thead><tbody><tr><td colspan="3">WHITE WHITE</td></tr><tr><td>Baryta White<br>Zinc White<br>Flake White</td><td colspan="2">YELLOW</td></tr><tr><td>Yellow Ochre<br>Raw Sienna<br>Naples Yellow<br>Cadmium Yellow<br>Cadmium Orange</td><td>Aureolin<br>Baryta Yellow<br>Indian Yellow<br>Strontia Yellow<br>Chrome Yellow</td><td>King's Yellow<br>Yellow Madder<br>Brown Pink; Yel. Lake<br>Gamboge<br>Zinc Chromate</td></tr><tr><td colspan="3">RED</td></tr><tr><td>Vermilion<br>Indian Red<br>Light Red<br>Venetian Red<br>Red Ochre</td><td>Madder Carmine<br>Rubens Madder<br>Rose Madder<br>Madder Red<br>Purple Madder</td><td>Crimson Lake<br>Carmine<br>Burnt Carmine<br>Indian Lake<br>Scarlet Lake<br>Purple Lake</td></tr><tr><td colspan="3">VIOLET</td></tr><tr><td>Cobalt Violet<br>Manganese Violet</td><td>Mars Violet</td><td>Violet Carmine</td></tr><tr><td colspan="3">GREEN</td></tr><tr><td>Mr. Ox. of Chromium<br>Green Ox, of "<br>Cobalt Green<br>Green Ultramarine</td><td>Emerald Green<br>Terre Verte<br>Malachite<br>Madder Green</td><td>Verdegris<br>Sap Green<br>Green Vermilion, etc.</td></tr><tr><td colspan="3">AGE</td></tr><tr><td>ULTRAMARINE<br>Artificial Ultram.<br>Cobalt<br>Coeruleum</td><td>Smalt<br>Prussian Blue<br>Antwerp Blue</td><td>Indigo<br>Blue Verditer<br>Blue Ochre</td></tr><tr><td colspan="3">Browns and Blacks</td></tr><tr><td>Burnt Sienna<br>Raw Umber<br>Burnt Umber<br>Cappagh Brown<br>Verona Brown<br>Prussian Brown<br>Ivory Black<br>Charcoal Black<br>Lamp Black<br>Graphite</td><td>Madder Brown<br>Cologne Earth<br>Bitumen<br>Vandyke Brown, A.<br>(earthy)</td><td>Vandyke Brown, B.<br>(bitumenous)</td></tr></tbody></table>

CLASS I - Includes the truly permanent pigments.

CLASS II - Those which, though liable to a variable measure
change, may yet generally be allowed.

CLASS III - Should be definitely excluded from the palette.

CHURCH 258 - ***One example of this difficulty of classification - AUREOLIN is almost worthy of place in Class I, Indian Y. scarcely deserves inclusion in Class II. The action of mixed pigments on one another, though not as frequent as it

is supposed to be, creates another difficulty in our classification of permanent pigments.

TOCH'S LIST OF PERMANENT PIGMENTS.

TOCH 175 - List of pigments which can be mixed with each other or used separately, and which are not affected by light, nor do they interact on each other:

LAMP BLACK

IVORY BLACK

GRAPHITE

PLUMBAGO - Or any form of carbon or carbonaceous blacks.

ZINC WHITE - or any form of oxide of zinc.

PERMANENT WHITE - or any form of artificial barium sulphate.

VENETIAN RED

INDIAN RED

BURNT UMBER

RAW UMBER

RAW SIENNA

BURNT SIENNA

MARS REDS. ORANGE. BROWN AND PURPLE.

OXIDE OF CHROMIUM. TRANSPARENT.

OXIDE OF CHROMIUM. VIRIDIAN.

TERRE VERTE

VERMILIONS MADE OF SULPHIDE OF MERCURY

ULTRAMARINE BLUES. NATIVE OR ARTIFICIAL.

BROWN. BURNT UMBER AND ALL OXIDE OF IRON BROWNS.

CADMIUM YELLOW TO ORANGE.

TOCH 175 - From a chemical standpoint these are practically the only colors which may be mixed with each other that will not react, and I have promptly omitted an number of so called permanent colors in this schedule, such as, for instance, the madder colors, which I find will decompose when mixed with ochres, as well as if a faint trace of acid is left in the oil.

I have omitted the Madder Lakes, for although they are permanent, they cannot be indiscriminately mixed with other pigments.

TOCH 186 -

THE PIGMENTS WHICH ARE ABSOLUTELY PERMANENT WHEN USED ALONE BUT ARE NOT PERMANENT WHEN MIXED WITH OTHER COLORS.

MADDER LAKE

ANTWERP BLUE

PRUSSIAN BLUE

PARIS BLUE

VERMILION (made from sulphide of mercury)

PARA RED

LITHOL RED

HARRISON RED

ULTRAMARINE BLUE

COBALT BLUE

HOOKER'S GREEN (when made from prussian blue & raw sienna

OCHRE

FLAKE WHITE

The foregoing list of colors must be used with some judgment. Many of these colors are permanent when mixed with some other colors, but decompose when mixed with each other. For instance, Yellow Ochre and Madder Lake when used alone are permanent, yet two when mixed will decompose.

(See page opposite)

JACQUES BLOCKX Fils

"SERIES OF PERMANENT COLORS OF THE SAME NATURE WHICH CAN BE INTERMIXED WITHOUT ANY DANGER" - p.89

LIGHT (ENGLISH) RED      GOLDEN OCHRE      "And in general, all
MARS RED                 MARS YELLOW       natural or calcined
VENETIAN RED             ITALIAN EARTH     ochres and earths,
POUZZOLES RED            MARS VIOLET       provided they are
INDIAN RED               BROWN OCHRE       suitably purified."
BURNT SIENNA            OCHRE"BRUNE MATE"  (Dull Brown)
MARS ORANGE              MARS SCARLET       MARS BROWN
MARS YELLOW-ORANGE      ORANGE TRANSPARENT BROWN
YELLOW OCHRE

"SERIES OF PERMANENT COLORS OF DIFFERENT NATURE WHICH DO NOT DETERIORATE IN AN APPRECIABLE MANNER WHEN INTERMIXED"-p.90

LIGHT (ENGLISH) RED      LIGHT OLIVE GREEN
MARS RED                 MARIE COLLART GREENS
VENETIAN RED             LAMORINIERE GREEN
POUZZOLES RED            COBALT BLUE
INDIAN RED               COERULIUM BLUE
BURNT SIENNA            GUIMET'S ULTRAMARINE BLUE
MARS ORANGE             MARS VIOLET
MARS SCARLET            MARS BROWN
MARS YELLOW-ORANGE      TRANSPARENT BROWN
CADMIUM ORANGE          CASSEL EARTH
ITALIAN EARTH           IVORY BLACK
VERONESE GREEN*         BLUE BLACK
CELADON GREEN

*The "VERONESE GREEN" in Block's usage of the name is EMERALD OXIDE OF CHROMIUM (Hydrated oxide of chromium) the most permanent of all the colors.

(In Block's book it is called VERTÉ EMERAUDE, in the translation from which these notes are taken it is VERONESE G. It is the same as VIRIDIAN)

"COLORS WHICH TEND TO DISCOLOR WHEN THEY ARE MIXED WITH BLANC D'ARGENT"-p.92

DEEP MADDER LAKES      PERMANENT MADDER CARMINE
PURPLE MADDER LAKES     CASSEL EARTH

"COLORS WHICH TEND TO BLACKEN BLANC D'ARGENT AND WHICH CONSEQUENTLY SHOULD BE MIXED WITH ZINC WHITE."-p.92

VERMILION CHINA CINNABARS

"COLORS WHICH DETERIORATE WHEN MIXED WITH IRON COMPOUNDS"-p.92
NAPLES YELLOW COBALT VIOLET

37

MADDER - ALIZARIN

CLASS

COMPOSITION

Organic compounds

Madder: Made from the Madder Root.

Alizarin (or artificial Madder) is the Manufacture of artificial dyes from the anthracene of coal tar, of the two chief coloring matters, Alizarin and Purpurin, has almost extinguished the cultivation of the Madder Plant in Europe.

Both Alizarin and Purpurin are now manufactured artificially from anthracene. This compound occurs in coal tar, is a crystalline fluorescent hydrocarbon, and is used in processes this substance gives rise to Alizarin and Purpurin, which are in all respects identical with these coloring matters as derived from the Madder Plant itself. --Church, 170--178

PERMANENCE

CHURCH 176 - Although the Madder colors are very much less affected by light than are the pigments derived from Cochineal, yet it cannot be affirmed that any of them are absolutely permanent when continuously exposed.

TOCH 85 - Alizarin or Madder Lake may be considered as permanent color under certain conditions. After a lapse of three centuries, it has been shown that this color, when used intelligently, is permanent.

It is used as glaze over thoroughly dry color, it will remain permanent.

If Madder or Alizarin Lake is mixed with any mineral or metallic color such as OCHRE, LEAD SIENNA, etc., a chemical decomposition takes place, with the result that the Lake is bleached.

Madder Lake may be mixed with any oxide of iron, color which has been burnt, but may not be mixed with any raw Iron color.

TUSCAN RED

Madder or Alizarin may be mixed with INDIAN RED, forming a color known as TUSCAN RED, which is perfectly permanent.

May be mixed with Burnt Sienna, Burnt Ochre, Burnt Umber, etc., but not with Raw Ochre, Raw Sienna, or Raw Umber.

The safest use is to glaze over thoroughly dry ground.

Madder Lake deepens considerably when placed in a dark place. But it is revived when subjected to bright sun light.

REFERENCES

Real and artificial Madders, Make, Origin.

CHURCH -Permanence 176 575 177.346.152 Church, 170

VERMILION

| **CLASS** | **Sulphides** |
| :--- | :--- |
| **COMPOSITION** | HgS |
| **REFERENCES** | } ORIGIN } NATURE } HISTORY } Church, 165 } MAKE } TEST } |

**HISTORY** - Toch, 108 - Chinese Vermilion is one of the oldest pigments known to artistic painters.

**ORIGIN** - Vermilion is sulphide of mercury.

**MAKE** - Artificially made by mixing sulphur and mercury in the presence of an alkaline solution under heat and

**DIFFERENT** pressure.

**HUES** - Ranges in hues from a light orange to a deep scarlet.

**PERMANENCE**
Church 169 - In oil painting there are no permanent pigments, save the copper greens, with which Vermilion may not be safely mixed. Only when it contains impurities, such as free sulphur, does it darken Flake White.

**WITH LEAD W.**

**IN SUN**
Toch, 108 - **When used alone as an oil color and exposed to brilliant sun rays, it will darken considerably.**

**UNDER GLAZE**
**OR VARNISH**

**DRYING**

**With LEAD W.**
Winsor&Newton, -29 - The vermilions and cadmiums are likely to blacken White lead and the Chromes, if they have been unskillfully prepared, but not otherwise.

**With CHROMES.**

**DRYING**

**With PRUSSIAN BLUE**
Mixtures of Vermillion and Prussian Blue are of doubtful stability.

Vermilion continued

LIGHT RED

**CLASS** Oxides
**COMPOSITION** Chiefly Fe₂O₃
**REFERENCES** Toch p. 86
Church p. 179

**ORIGIN** Light Red is Yellow Ochre calcined.

**Permanence** Perfectly Permanent without action on other pigments -- Church p. 179

**Effect on LAKES** Safe with Madders and Lakes. - Toch p. 86

**RELATION TO MARS RED** Toch p. 141 - Light Red and Mars Red are identical, the latter being much more transparent.

MARS RED

GLASS

COMPOSITION

REFERENCES

Oxide.

Chiefly Fe₂ O₃

Toch p. 141

Church p. 157

ORIGIN

Similar to Mars Orange (composed entirely of hydrated oxide of iron which has been properly precipitated and washed) with the exception that it has been heated until the water of combination is driven off.

PERMANENCE

EFFECT ON
LAKES

Toch p. 141 - It is a soft, permanent color.

Supposed to attack certain Lakes but it is
doubtful if it does.
give contending
evidence of other authorities
here

Dries well.

RELATION TO
LIGHT RED

Identical with Light Red but much more trans-
parent.

VENETIAN RED

| **CLASS** | Oxides  |
| :--- | :--- |
| **COMPOSITION** | Chiefly Fe₂O₃  |
| **REFERENCES** | Church 179, 180  |
| | Toch 168 |

ORIGIN

Church 179 - Originally Venetian Red consisted of a native ferric oxide or red haematite, less purple than Indian Red.

Of recent years the name has been transferred
to a particular quality of artificial ferric
oxide, made by calcining green vitrol.

Toch 168 - Venetian Red is a pure bright form of oxide of iron.

The Venetian Red of commerce is a mixture of
Gypsum and oxide of iron more permanent than
pure oxide of iron, neither fades or darkens,*
but should n't be mixed with any Lakes.

(Church's book is 1901, Toch's 1911)

PERMANENCE

Church 180 - Few commercial samples will stand the test of being free from soluable salts and from any trace of sulphates.

Church 180 - Venetian Red whether artificial or
natural, is a permanent pigment which may be
mixed with other permanent pigments without fear
of injuring them.

Toch 168 - Permanent. Dries well. Reliable. But has tendency to darken when exposed to bright light. (See above*)

EFFECT ON
LAKES

Decomposes Lakes.

["INDIAN RED", "**CLASS** Oxides\n**COMPOSITION** Chiefly Fe2 O3\n**REFERENCES** Church 180\nToch 131", "ORIGIN", "Church 180 - Contains about 95% of ferric oxide\nIs a variety of Red Ochre, or Red Haematite.\nMost of the Indian Red from India is a natural\nproduct, but some has been prepared by calcination.", "Toch 131 - Is true oxide of iron. Contains no\nwater in its combination.", "PERMANENCE", "Church 180 - Genuine Indian Red perfectly permanent.\nNo action on other colors.", "OPACITY", "Toch 131 - Extremely Permanent. Dries well.\nHas enormous hiding power (opacity).", "AS GROUND FOR FLESH TINTS Is very reliable when mixed with Zinc Oxide to produce a ground for flesh tints - Toch 131", "EFFECT ON LAKES", "Indian Red does not decompose Madder Lake.", "DIFFERENT TONES OF INDIAN RED", "There are many tones of Indian Red.\nSome produce a violet when mixed with White,\nand others a distinct pink or rouge.", "RELATION TO TUSCAN AND POMPEIIAN RED", "When Indian Red is tinted with Madder it is sometimes called TUSCAN or POMPEIIAN RED", "RELATION TO MARS VIOLET", "Mars V. is very dark form of Crocus Martis, or Indian Red. Is nothing more or less than a purple oxide of iron. Very durable. Dries well. Is permanent to light. - Toch 141", "COMPARISON OF DIFFERENT MAKES OF INDIAN RED", "R. H.- (Feb. 1920) - Differing tones of I.R.\nHatfield's - - - - - - - - - - - - - - - -

MARS VIOLET

CLASS Oxide.

COMPOSITION Chiefly Fe₂ O₃

REFERENCES
* Toch p. 141
* Church p. 157

ORIGIN
Toch p. 141 - A very dark form of Crocus Martin's or Indian Red.

PERMANENCE
Toch p. 141 - Very durable. Dries well. Permanent to light.

EFFECT ON LAKES
Safe.

RELATION TO INDIAN RED
Practically the same. More violet than most samples of Indian Red.

BURNT UMBER

CLASS Oxides

Composition Oxides of Fe and Mn.

REFERENCES Church p. 229

Toch p. 100

ORIGIN Church 229 - Burnt Umber is Raw Umber calcined.
Raw Umber is not an ordinary ochre but owes its
color to manganese.

Toch p. 100 - Similar to Burnt Sienna.

PERMANENCE Church p. 229 - Permanent. No action on stable
pigments.

DRYING Toch p. 100 - Permanent and reliable.
One of the best drying pigments in existence.

AS A
BACKGROUND
COLOR
Many painters mix Burnt Umber with their pig-
ments for producing dark backgrounds in order
to obtain a good drying surface.

CRACKING Care must be exercised not to paint it over a
soft or semi dry ground or cracks will result.

EFFECT ON
LAKES
Safe with Lakes.

BURNT SIENNA

**CLASS**
**COMPOSITION**

Oxides.
Chiefly Fe₂O₃

**CHURCH 231 -**
Raw Sienna roasted or calcined becomes Fer-
ric oxide.

**TOCH 99 -** ***Very much similar to composition to BURNT OCHRE, excepting that its content of oxide of iron is very much larger, and the physical characteristics differ from those of Ochre. Ochre opaque, Bt. Sienna translucent.***

**PERMANENCE**
**EFFECT ON LAKES**

TOCH 100 -
One of the most permanent colors in existence excepting the lighter shades which have not been so well calcined. These have a strong tendency to darken and become redder.

Can be mixed with Lake Colors.
Exceedingly rich tints are produced by glazin Lakes over dry Sienna, which are absolutely permanent, provided the Lake itself is permanent.

**CHURCH 231 -** Permanent and without action on other pigments.

**TOCH 100 -** Bt. Sienna is excellent drier. Will mix with almost every other perm. color.

**THE MARS COLORS**
**TOCH 100 -** The Mars Colors are nearly all artificial siennas and are just as permanent

**RELATION OF MARS ORANGE TO Bt. SIENNA**
Mars Orange is similar to Bt.Sienna. sometimes called "Extract of Bt.Sienna" because it is composed entirely of hydrated oxide of iron properly precipitated and washed. Mars Orange is identical with ordinary iron rust. - TOCH 140

**EFFECT OF MARS O. on LAKES**
**DECOMPOSES LAKES.** - TOCH 140

**CRACKS**
**HARD DRIER AND TENDENCY TO CRACK.** - TOCH 140
**DARKENS ON EXPOSURE.** - TOCH 140

**OTHER FAULTS OF MARS ORANGE**
**TONES MIXED WITH WHITE HAVE TENDENCY TO SADDEN ON EXPOSURE.** - TOCH 140

MARS ORANGE

CLASS

COMPOSITION

REFERENCES

Toch p. 140 - Church 157

ORIGIN

Toch p. 140 - Composed entirely of hydrated oxide of iron which has been properly precipitated and washed.

It is identical with ordinary Iron Rust.

PERMANENCE

Toch p. 140 - Very hard drier. Has tendency to crack.

Darkens on extreme exposure.

When mixed with White saddens on exposure.

EFFECT ON
LAKES

Decomposes Lakes.

RELATION TO
BURNT SIENNA

Has sometimes been called Extract of Burnt Sienna.

RAW SIENNA

**CLASS** Hydrates.
**COMPOSITION** Oxides and hydrates of Fe and Mn.
**REFERENCES** See Church229,252.254, See Toch p. 154

**ORIGIN** Church p. 229 - Is an earth, found chiefly in Tuscany and the Hartz.
Is a rich variety of Yellow Ochre.
Contains large proportion ferric hydrate.

**PERMANENCE** Church p. 230 - Liable to become rather less brown and more yellow by long exposure to strong light.
Without action on other pigments.

**EFFECT ON LAKES** Toch p. 154 - Safe with all colors except the Lake Colors.

**RELATION TO MARS YELLOW** Mars Yellow is sometimes called extract of Yel. Ochre or extract of Raw Sienna, because it is composed of the coloring matter of these two pigments. Very like Raw Sienna. Is permanent, dries well and is translucent. ---Toch p. 141

**PERMANENCE** Toch p. 154 - One of the safest colors to use.
Works well with every color, except the Lakes.
Is four times as strong as Yel. Ochre -- that is, contains four times as much iron.
Absolutely permanent with the possible exception that it darkens very slightly after many years.

MARS YELLOW

CLASS

COMPOSITION

REFERENCES

Toch p. 141

Church p. 142 157

ORIGIN

Toch p. 141 - Mars Yellow has been called Extract of Ochre, or Extract of Raw Sienha because it is composed of the coloring matter of these two pigments.

PERMANENCE

Toch p. 141 - Permanent. Dries well and is translucent.

EFFECT ON
LAKES

Decomposes Lakes.

RELATION TO
RAW SIENNA

Very similar to best Raw Sienna.

AS A GLAISE - Found particularly useful as a glaze

YELLOW OCHRE

CLASS
COMPOSITION
Hydrates
Fe₂O₃.nH₂O

CHURCH 138 - Yellow ochre is a ferric hydrate (Red Ochre is ferric oxide)

CHURCH 139 - An analysis of a fine example of Yellow ochre from a pit on Shotover Hill near Oxford gave the following percentages:

Hygroscopic moisture--7'1 : Magnesia .................... 0'3
Combined water--------9'0 : Silica------------------61'5
Ferric oxide----------13'2 : Calcium sulphate------- 1'4
Alumina-------------- 6'3 : Undetermined------------ 1'2

The varying hues of Yellow Oochres depend mainly on two differences of composition.

One of these is the amount of white clay, silica, calcium sulphate, or barium sulphate present in them. This lightens the color.

The other is the presence of ferric oxide which gives them a ruddier or warmer hue.

All ochres when burnt - that is, calcined - lose their essential water, and become converted into various kinds of Red Ochre, Light Red, etc.

The varieties which contain much silica and clay (ingredi-ents which, even in good yellow ochres, often amount to two thirds of their weight) yield the less translucent and paler tints of some of the burnt red ochres.

Excellent Oochres come from Dubbo, New South Wales. English Oochres from Oxfordshire and Derbyshire, etc., are of fine quality. --CHURCH 139

HISTORY
CHURCH 140, 141

Yellow Oochre was used by the Egyptians, Greeks, Romans
***Stood with very little change test of centurys.
***Slightly darker and warmer after prolonged exposu-
re to light.

PERMANENCE
CHURCH - Yellow Oochre is without action on other
pigments.

EFFECT ON
LAKES

It is possible that ochre may injure the
hue of some lakes, such as YELLOW LAKE,
and CRIMSON LAKE *** but as such Lakes
are Worthless**** --CHURCH 141

R.H. -Judging from the above Church allows the mixing of Yellow Ochre with Madders and Alizarins.

TOCH 138 - The Madders are all permanent except when mixed with the OCHRE and sienna pigments, white lead, Chrome Yellow, chrome green and metalic pigments of that nature.

TOCH 171 - Native clay colored with about 20% of Iron rust

YELLOW OCHRE - continued

**PREFERENCE**
continued

TOCH 172 - Very permanent, and can be mixed with other mineral pigments.

**ON LAKES**
**IN LIGHT**

It has the same destructive effect on the LAKE CO LORS that the sienna earths and other Ochres have

When exposed to the bright light for a year, it has the tendency to darken very slightly.

**DRYING**

Good drier.

**RELATION**
**TO LIGHT RED.**

LIGHT RED is burnt Yellow Ochre. In this form, of Light Red it does not decompose Madder.

**OTHER NAMES FOR YEL. OCH.**

ROMAN OCHRE
MINERAL YELLOW
OXFORD OCHRE

GOLDEN OCHRE
BROWN OCHRE
OCRE JAUNE

GELBER OCKER

**ADULTERATION**

CHURCH 142 - A frequent adulteration of Y.O. is the addition of Chrome Yellow -- that is, Lead Chromate.

**BROWN OCHRE**

Church 142 - Brown Och. is an approximately pure Limonite.

CADMIUM

**CLASS** Sulphides
**COMPOSITION** CdS
**REFERENCES** Toch 101
Church 250(M. Paul de Lapparent), 142
C, Moreau-Vauthier 167

**OTHER NAMES FOR CADMIUM**
Aurora Yellow
Daffodil
Sulphide of Cadmium
Cadmium Gelb
Orient Yellow
Orange Cadmium
Jaune Brilliant
Jaune de Cadmium

**ORIGIN**

Church 142 - The Metal Cadmium, which is nearly related to Zinc both chemically and physically, was discovered by Stromeyer in 1817.

Church 142 - To one compound only of cadmium, the sulphide, are due all the hues and tints of red from the palest lemon cadmium to the firey orange-red. This compound is CdS, and contain 112 parts by weight of cadmium to 32 parts of sulphur.

Toch 101 - All the Cadmium Colors are manufactured by precipitating a salt of Cadmium with a salt containing a sulphide, so that the Cadmiums are sulphides of cadmium.

According to the speed of precipitation, temperature of the solutions, admixture of acids or alkalies, all shades from brilliant yellow to the deepest orange are found.

**PERMANENCE**

Toch 101 - Cadmium Yellow may be regarded as a perfectly permanent pigment.

**DRYING**

Toch 101 - The Cadmiums are slow but reliable driers and may be mixed with all other chemical pigments, even Flake White, without decomposing.

**PERMANENCE WITH FLAKE W.**

Much has been written on the supposed reaction which take place between this and other pigments.

**PERMANENCE WITH WHITE LEAD**

It is said, though being a sulphide, it should not be mixed with a Lead Color, because the sulphur in the Cadmium would combine with the lead with a blackening effect.

Ordinarily this is not so. Cadmium Sulphide is a very stable chemical compound and will not give up its sulphur as readily as ARTIFICIAL ULTRAMARINE BLUE will, for instance.

There should be no hesitancy in using Cadmium

CADMIUM - continued

AURORA YELLOW
continued

Drying
Manganese Oil accelerated the drying of Cadmium which is sometimes slow in drying. - Church 148

PALETTE KNIFE WITH CADMIUM
Church - It is perhaps safer to employ Ivory knife rather than steel in manipulating Cadmium pigments.

EFFECT WITH YELLOW OCHRE
Church - Cites bad effect of cadmium with C CHROME and with YELLOW OCHRE when the latter has been made more brilliant by addition of CH CHROME.

Evidently Cadmium and true YELLOW OCHRE are OK

NAPLES YELLOW REPLACED BY CADMIUM
Church 147 - Cadmium with ZINC or FLAKE WHITE replace true NAPLES YELLOW.

AUREOLIN

CLASS
COMPOSITION
Inorganic Salts.
$K_5Co_212NO_2$

CHURCH 148 - ***compound of the nitrates of
Cobalt and Potassium

OTHER NAMES
Cobalt yellow.

PERMANENCE
CHURCH 148 149 150
Does not fade or darken in sunlight --- whatever darkening due to oil.

Good drier when properly prepared.

O. K. with VIRIDIAN, p. 194

VIRIDIAN with Aureolin produces fine colors.

LEMON YELLOW may be safely associated with Aureolin.

CHARCOAL BLACK yields with Aureolin a series
of greens quite distinct from mixing same
with Ivory Black.

EFFECT ON
LAKES
CHURCH refers to the effect of Aureolin on the
Lakes by saying that that Aureolin accelerates
the fading of fugacious organic pigments, such
as the Lakes from Cochineal.

Generally Church speaks highly of Aureolin.

WINSOR & NEWTON 26 - Mixing Aureolin and Madder Lake or Alizarin is questionable.

Mixtures of Aureolin with organic pigments
should be regarded with suspicion.

TOCH 90 -
Its permanence depends entirely on its purity.

TOCH admits that there is a variation of opinion as to its permanence.

Some claim that it is absolutely permanent in
both water and oil.

Others claim that it decomposes with a White.

If the color is thoroughly washed by the manufacturer after it is precipitated in order to free it from soluble salts, it may be regarded as absolutely permanent, because it is not affected by sulphur gases nor by sun light.

If impure, will decompose Lakes, and when mixed with raw linseed oil, loses brilliancy in short time. There are several good manufacturers of this pigment, whose Au, may be used and regarded as absolutely permanent. For safety sake it is advisable to use it alone and not mix it with any Lake pigment. Lake glazed over it, after it is dry, does not affect either the Lake or the Aureolin.

LEMON YELLOW

OTHER NAMES

BARYTA YELLOW

YELLOW ULTRAMARINE

JAUNE D'OUURREMER

BARIUM CHROMATE

PERMANENT YELLOW

CLASS

COMPOSITION

Chromates.

CHURCH

Church 152 -

Of all the Chromates which have been used in
painting BARIUM CHROMATE is the most stable.

Lemon Yellow is Barium Chloride and Potassium Chromate.

PERMANENCE

Properly prepared Lemon Yellow may be mixed
with most other stable pigments without suffering change.

It is not blackened by sulpheretted hydrogen

EFFECT ON
LAKES. ETC.

May be safely associated with AUREOLIN, with
MADDER CARMINE and with PRUSSIAN BLUE.

SUBSTITUTES

Strongian Chromate is often substituted for
true Lemon Yellow and is less reliable.

ADULTERATIONS

The most common adulteration of Lemon Yellow
is with pale Chrome which blackens under
sulphurretted hydrogen.

LEMON YELLOW

TOCH

COMPOSITION

Toch 137 - Lemon Yellow may be either:

CHROMATE OF BARIUM or

CHROMATE OF STRONTIUM

PERMANENCE

Is similar to Chromate of Zinc, in many
respects. May be regarded as a reliable,
permanent color.

EFFECT WITH
SIENNAS AND
OCHRES

Can be mixed with almost every color, excepting those containing hydrated oxide of iron such as Siennas and Ochres.

It cannot supplant ZINC YELLOW and may there
fore be omitted.

ZINC YELLOW

OTHER NAMES Primrose Yellow ----- Zinc Chromate

CLASS Chromate.

COMPOSITION ZnCrO₄ (zinc chromate), or

Composition
Various
Toch 151 - May be pale variety of CHROMATE OF ZINC.

or a mixture of CHROMATE OF ZINC and CHROMATE of BARIUM.

or CHROMATE OF ZINC and OXIDE of ZINC.

PERMANENCE Toch 151 - In any of the above cases it is a safe, permanent, reliable color.

Dries fairly well, particularly when exposed to light.

Not affected by sulphur gasses.

EFFECT ON
LAKES

Cannot be mixed with a lake color.

PRIMROSE
YELLOW
Church, 152 - (from Church's remarks under Lem ZINC CHROMATE and CALCIUM CHROMATE are yellow pigments of inferior value.

A mixture of ZINC CHROMATE with BARIUM CHROMATE is sold as "Primrose Yellow".

VIRIDIAN

OTHER NAMES

EMERALD OXIDE OF CHROMIUM.

VERTE EMERAUDE

VERTE DE GUIGNET

VERTE PANNETIER

MITTLER'S GREEN

CLASS

COMPOSITION

Hydrates.

Cr₂O₃·2H₂O

Church 194 - ***About 8 parts crystalised

Boric Acid and 3 parts of potassium bichromate
mixed, calcined, washed.

The product is a hydrated chromium sesquioxide

Viridian is essentially a hydrated sesquioxide
of chromium.

TOCH 170 - ***Form of chrome oxide***has all
chariarieties of oxide of chromium, and has
the same chemical composition with the addit-
ion of water as a hydrate or water of combi-
nation.

PERMANENCE

CHURCH 194 -

Unaffected by sunlight.

Unaffected by sulphurous hydrogen.

Can be used with all the different painting
media, and upon all kinds of painting ground
ds.

No action on other pigments.

TOCH 170 -

Thououghly safe and reliable.

When exposed to light does not show any per-
ceptable change.

Not affected by any gasses in the atmosphere.

Dries well.

EFFECT ON
Lakes

Safe with madders and all colors.

CHURCH 194 - ***Produces fine colors with
AUREOLIN and ULTRAMARINE.

# VIRIDIAN

## (EMERALD OXIDE OF CHROMIUM.)

### OTHER NAMES

VIRIDIAN

EMERALD OXIDE OF CHROMIUM

VERONESE GREEN

VERTE EMERAUDE

VERTE PANNETIER

VERTE DE GUIGNET

MITTLER'S GREEN

### CLASS

HYDRATES.

### COMPOSITION

Church 194 - Viridian is essentially a hydrated sesquioxide of chromium having the formula $Cr_2O_3 \cdot 2H_2O$

Toch 170 - Form of Chrome Oxide.

Has all the characteristics of oxide of Chromium with the addition of water as a hydrate or water of combination.

WINSOR & NEWTON 16 - A hydrated and very transparent variety of Chromium Sesquioxide

### HISTORY

Winsor & Newton 16 - Originally introduced by our house.

Church 194 - Pannetier and Binet 1830
Later by Guignet.

### PERMANENCE

CHURCH 195 - Quite unaffected by sunlight and its sulphuretted hydrogen, has no action on other pigments, may be safely used with all painting media and on all kinds of painting grounds.

TOCH 170 - Safe and reliable.

Dries well.

Safe to sunlight and not affected by any gases in the atmosphere.

MARS BROWN

CLASS Hydrates.

COMPOSITION Oxides and Hydrates of Fe and Mn.

REFERENCES Toch p. 140 - Church p. 157

ORIGIN Similar to Raw Umber.

PERMANENCE Toch p. 140 - Of itself it is perfectly permanent. Is a very good drier.

EFFECT ON Decomposes Lakes.

LAKES Must not be mixed with any of the Lakes.

RELATION TO Similar.

GENUINE ULTRAMARINE

**OTHER NAMES**
Lapis Lazuli Blau --- Lasurstein Blau ---
Outremer --- Bleu d'Azur.

**CLASS**
Sulphides.

**COMPOSITION**
Contains Si, Al, Na, O, S.

Ultramarine Blue whether it is genuine or artificial is chemically the same. ---TOCH 163

Genuine Ultramarine Blue is the powdered mineral known as Lapis Lazuli ---TOCH 163

For description of, and manufacture of Lapis Lazuli Blue, see CHURCH 203

**PERMANENCE**

TOCH 163 - The only advantage that the genuine has over the artificial is that the genuine is not so quickly affected by acids as the artificial is.

Toch 112 - Ultramarine is exceedingly permanent except when mixed with another pigment which contains Lead, like

Flake White.
White Lead.
Chrome Yellow.
Chrome Green.

It should be kept away from colors containing
Copper,
Lead,
Iron.

And such Metalic Bases as are affected by
Sulphuretted Hydrogen.

CHURCH 204 - It is generally considered that Ultramarine withstands the action of light, moisture and SULPHURETTED HYDROGEN perfectly, and that it neither affects nor is affected by any other pigments.

**GENUINE ULTRAMARINE ASH**

TOCH 163 - Ultramarine Ash is a weak variety of genuine ultramarine blue, (Or may be of Artificial)

**PERMANENCE**

TOCH 163 - Do not mix it with Lead.

2

93

ARTIFICIAL ULTRAMARINE

Names -

<table><tr><td>ULTRAMARINE BLUE</td><td>NEW BLUE</td><td>BRILLIANT ULTRAMARINE BLUE</td></tr><tr><td>FRENCH ULTRAMARINE</td><td>COBALT</td><td>PERMANENT BLUE</td></tr><tr><td>GMELIN'S BLUE</td><td>OUTREMER</td><td>FRENCH BLUE</td></tr><tr><td>GUIMET'S BLUE</td><td>ORIENTAL BLUE</td><td>HENMANN'S BLUE</td></tr><tr><td>ULTREMARINE ASH</td><td>CERULEAN BLUE</td><td>GREEN ULTRAMARINE</td></tr><tr><td>VIOLET ULTRAMARINE</td><td></td><td>LILAC ULTRAMARINE</td></tr><tr><td>PURPLE ULTRAMARINE</td><td></td><td>RED ULTRAMARINE</td></tr></table>

**CLASS** Sulphides.

**COMPOSITION** Contains Si, Al, Na, O, S, Ultramarine Blue whether it is artificial or genuine is chemically the same. --Chuch206

First made about 1826 by C. Gmelin and by Guimet. --Church 206

Artificially made by J. B. Guimet in France in 1826 --Toch163

CHURCH(Date of Church's book 1901) --Now chiefly made in Germany and France.

Toch 122 - U. S. A. now the largest producers of Ultramarine Blue. ( Date of Toch's book 1911)

Toch163 - Contains Alumina, Silica, Soda, and Sulphur.

When made by means of a potash salt instead of a soda salt Ultramarine has every analogy of color and shade to genuine Cobalt Blue, excepting that Cobalt Blue(genuine) is not affected by acids as rapidly as the artificial.

TOCH 122 - There are no less than 20 shades of French Ultramarine ranging from the palest Cobalt to the deepest Ultramarine.

CHURCH 206 - The raw material employed in the preparation of Ultramarine are

Kaolin, or China Clay,

Silica,

Sodium sulphate,

Sodium carbonate,

Sulphur,

Charcoal,

Rosin,

Some makers omit the Sodium Sulphate
Others omit the - - - Rosin.

Calcined Alum is occasionally substituted for the Kaolin.

(Continued)

ARTIFICIAL ULTRAMARINE - continued

PERMANENCE

CHURCH - Artificial Ultramarine, when properly prepared, is permanent both in water and oils.

TOCH 163 - The Artificial Ultramarine is just as good as the genuine, and the only advantage that the genuine has over the artificial is that the genuine is not so quickly affected by acids as the artificial is.

Ultramarine is exceedingly permanent, except when mixed with another pigment which contains Lead, like

Flake White,
White Lead,
Chrome Yellow,
Chrome Green.

It should be kept away from colors containing COPPER, LEAD, and IRON. (state the colors)

And such metalic bases as are affected by SULPHURETTED HYDROGEN. ---TOCH 112 (state the colors)

CHURCH - If an Ultramarine should discolor EMERALD GREEN, CHROME YELLOW, TRUE NAPLES YELLOW, FLAKE WHITE,

it probably contains free sulphur, or has been insufficiently washed.

CHURCH 207 - Neither Sulphuretted Hydrogen nor caustic lime, or other alkaline substance affects the color of Artificial Ultramarine.

WITH ZINC WHITE

TOCH 122 - When used with ZINC WHITE or alone it is absolutely permanent.

GUIMET'S HENMANN'S

CHURCH - The Ultramarines known as "GUIMET'S" and "HENMANN'S" are of fine quality.

GREEN, RED, VIOLET, LILAC, PURPLE.

CHURCH - The Green, Violet, Lilac, Purple, Red ultramarines of commerce are permanent pigments of some artistic value.

TO TEST ULTRAMARINE & See Church 208

TOCH 163 - When made by means of a Potash Salt instead of a Soda Salt Ultramarine has every analogy of color and shade to genuine Cobalt Blue, excepting that genuine Cobalt Blue is not affected by acids as rapidly as the artificial.

SILICA IN ULTRAMARINE

See CHURCH 208

See TOCH 164

Toch places Ultramarine in his exclusive list of permanent and mixable colors.

HE ALSO PLACES IT IN HIS PERMANENT LIST OF PERMANENT, BUT NOT MIXABLE WITH CERTAIN OTHER COLORS. (SEE PAGE 29. THIS BOOK FOR THESE LISTS)

NEW BLUE

TOCH 146 - NEW an artificial
Cobalt = Cobalt shade. Artificial Ultramarine of the

WINSOR & NEWTON -- A pale variety of French Ultramarine.

TOCH 146 - Artificial Ultra marine of Cobalt shad
Perfectly permanent, except when mixed with White
Lead or Flake White, or any other color containing
Lead. Must not be used in conjunction with
a LEAD DRIER.

By itself it is absolutely permanent. Dries well.

References

See all under heading: "Artificial Ultramarine"

FRENCH BLUE

FRENCH

ULTRAMARINE

TOCH 121 - Absolutely permanent to light.

Dries fairly well.

Can either be used as glaze or solid

Identical in composition with the gen-
une Lapis Lazuli. The author cannot find it in-
inferior in any respects to the natural stone.

Must never be mixed with any FLAKE WHITE, CHROME
YELLOW, CHROME GREEN, or any pigment containing
a metalic base, except ZINC.

This pigment should never be mixed with any other
pigment which the free sluphurous acid is likely
to decompose.

COMPOSITION

See Composition of "Artificial Ultramarine".

CHURCH 207 - Neither Sulphuretted Hydrogen nor
caustic lime, or other alkaline substance affec-
ts the color of Artificial Ultramarine.

If an ultramarine should discolor Emerald Green,
Chrome Yellow, True Naples Yellow, or Flake Wt.,
it probably contains free sulphur or has been
insufficiently washed.

WINSOR & NEWTON & Class I* Of the finest brands
obtainable.

TOCH 122 - There are no less than twenty shades
of French Ultramarine ranging from the palest
Cobalt to the deepest Ultramarine.

BRILLIANT
ULTRAMARINE
BLUE

TOCH 94 - Assumed to be artificial ultramarine blue when made by calcining sulphur, clay and sulphate of soda.

Permanent to light when used alone and when used with certain of the colors on which it has no influence. (See page 95)

WINSOR & NEWTON - CLASS 6I* - Of the finest brands of artificial ultramarine obtainable.

ORIENTAL BLUE

CHURCH 208 - An ultramarine with a plus of silica.

SILICA IN ULTRAMARINE - See Church 208.
See Toch 164 165

add significance of this silica on perm.

CERULEAN BLUE

Other Names= COERULEUM. CERULIUM, COELINELAU, BLEU CELESTE.

CLASS
COMPOSITION

Oxides. }} This refers to the True Cerulian
CoO, SO2 }}

Origin
PERMANENCE
ETC

TOCH 106 - In the present age Cerulean Blue is an artificial ultramarine of a pale shade, made by grinding artificial Cobalt with a mixture of Zinc Oxide.

Appears blue under gas or electric light.
Perfectly Permanent. Can be mixed with any pigment except those containing Lead.

SUBSTITUTES
FOR CERULEAN
BLUE

Ordinary Cobalt Blue mixed with White will produce practically the same shade and effect.

CHURCH 212 - May be imitated by ultramarine, Viridian and White.

R. H. - I find Cerulian Blue Best imitated by mixing Cobalt Blue, Viridian and Zinc White. (Used Remb. Cob. Extra, W&N Virid. Remb. Z.W.) Some Ultram. B. are too purple to make a clear note with Viridian.

W&N CERULEAN

Class I* - Stannate of Cobalt.

MAKE OF
GENUINE

See Church 212 for the different ways of making genuine Cerulean Blue.