CERTAIN IMPROVEMENTS IN THE PREPARATION AND APPLICATION OF COLORS SUITABLE FOR PRINTING STUFFS COMPOSED OF SILK OR WOOL, OR OF A MIXTURE OF SILK AND WOOL
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
CLINTON ROBERTSON, of 166, Fleet Street, in the City of London, Civil
Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of
Great Britain and Ireland, bearing date at Westminster, the Tenth day of
December, One thousand eight hundred and forty-seven, in the eleventh year
of Her reign, did, for Herself, Ier heirs and successors, give and grant unto
me, the said Joseph Clinton Robertson, my exors, adñiors, and assigns, Her
especial license, full power, sole privilege and authority, that I, the said
Joseph Clinton Robertson, my exors, adññiors, and assigns, or such others
as I, the said Joseph Clinton Robertson, my exors, adiñors, or assigns, should
at any time agree with, and no others, from time to time and at all times
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, and in the Islands of Jersey, Guernsey, Alderney, Sark, and
Man, and in all Her said Majesty's Colonies and Plantations abroad, the
Invention of "CERTAIN IMPROVEMENTS IN THE PREPARATION AND APPLICATION OF
COLORS SUITABLE FOR PRINTING STUFFS COMPOSED OF SILK OR WOOL, OR OF A
MIXTURE OF SILK AND WOOL," communicated to me from abroad; in which
said Letters Patent is contained a proviso, that I, the said Joseph Clinton
Robertson, should cause a particular description of the nature of the said
Invention, and the manner in which the same is to be performed, by an

page_text: instrument in writing under my hand and seal, to be inrolled in Her said
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as in
and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Joseph Clinton Robertson, do hereby declare that the nature of the said In-
vention, and the manner in which the same is to be performed, are fully
described in and by the present Specification thereof, that is to say:-
Whereas the coloring matters hitherto employed in printing textile fabrics
composed of wool, of silk, and of wool and silk combined, are usually in the
state of extracts which are obtained by aqueous solution from various kinds of
dye woods, and from other substances, such as orchil, cochineal, &c., &c.,
and by evaporating more or less these extracts; but it often occurs that, in
using boiling water to extract these coloring matters several other soluble
substances are extracted along with them, so that when an aqueous solution of
any coloring matter is evaporated, the residuum retains a great deal of these
extraneous substances, and consequently produces colors less brilliant than if
it were isolated and pure. Again, all aqueous extracts, particularly highly con-
centrated ones, deposit in the course of time the whole of the coloring matter
which is in a state of suspension, and likewise, in the majority of cases, a
resinous substance, which has probably mixed up with it a portion of the
coloring matter. And as the concentration or strength of the extract
diminishes in proportion as the deposit increases, it follows that the liquor in
any two vats must always vary more or less in strength according as one may
have stood longer than the other.
Now, such differences of intensity necessarily cause irregularities in the
printing of goods; moreover, there are still greater irregularities arising from
the fact, that all extracts have not equal affinities for water, and consequently
that some have a greater tendency than others to absorb steam, from which
causes combined steam printing (le vaporisage) is rendered an operation ex-
tremely uncertain in its effects, and very liable to accidents. It has been usual
to give to this process the name of "dry dyeing" (teintine seche), which would
seem to imply that the employment of water is unnecessary, which, however,
is not the case, for all manufacturers are careful to keep the goods moist which
they wish to fix with the colors, either by placing them in a humid atmosphere
or by damping them during the process of steaming by opening the steam cock
a little at the commencement of the operation, so that the steam which escapes
may be condensed upon the goods, and thereby impart to them the necessary

page_text: degree of humidity. Without these precautions the colors would be feeble
and spotty in appearance, unless, indeed, the colors can be previously rendered
equally hygrometric, which it is an extremely difficult thing to effect. If two
pieces of the same printed fabric are submitted to the process of steaming, one
very dry and the other very damp, the color of the first will be feeble and
spotty, while that of the second will be bright and full-bodied.
All printed
woollen goods, with the exception of those which are printed with colors which,
like French blue, have a great affinity for water, require, in order to the colors
being firmly fixed, to have condensed on them the largest possible quantity of
steam either before or during the process of steaming, but without the quantity
being so large as to allow of running (coulage); and if it should happen that
in the same piece and by one and the same operation the color runs in one
part, is weak in another, or is clear and decided in a third, it must arise from
the piece not having in all parts an equal affinity for water. To remedy the
various inconveniences arising from the use of extracts in steam dyeing
(vapourisage), it is necessary to replace those extracts by preparations in which
the coloring matters are in a purer and more unalterable state, and which such
that they may be fixed in the goods in an uniform manner, and at a degree of
humidity as analagous as possible to that of the dyeing bath; and this is what
has been effected by the improvements to be now described.
These improvements are founded on the general fact that if to a decoction
on any coloring matter (a decoction of fustic, for instance) there be added a salt,
such as the chloride of protoxide of tin, the base of which has a great affinity
for the coloring matter, an insoluble precipitate results, which holds very little
if any extraneous soluble matter, and contains the coloring principle in a state
of much greater purity than the ordinary extracts. Although insoluble, this
precipitate is capable of combining perfectly with the textile fabrics aforesaid,
provided the steam printing is performed while the goods are well damped.
In consequence of the insolubility of this precipitate, the color obtained by
means of it may be fixed by steam without any previous desiccation, and goods
which may have been dried after printing may be again wetted without danger
of the colors running. The precipitates which may be thus obtained and
applied are numerous, but as they are all very similar in effect, it may suffice
to specify those only which appear to be most susceptible of general use.
To obtain a precipitate of Cuba wood (morus tinctoria): dissolve in water
about one hundred parts of chips, strain this solution through a silk cloth, and
then pour into it by little and little (stirring the mixture the while), a solution
of ten parts of deuto-chloride of tin dissolved in twenty parts of water and four
parts of sulphuric acid of sixty-six degrees. When the precipatate has been

page_text: deposited, draw off the supernatent liquid and wash it repeatedly with fresh
water till no trace of the acid remains. The precipitate is then to be filtered,
and kept in a humid state till required for use.
To obtain a precipitate of fustick (rhus cotinus): dissolve in water about one
hundred parts of chips, strain the solution through a cloth, and then pour into
it by little and little, stirring it as before, a solution of ten parts of chloride
of tin in twenty parts of hot water. When the precipitate thereby produced
is deposited, draw off the supernatant liquid, and filter (without any previous
washing). This preparation is also to be kept damp.
To obtain a precipitate of woad: make a solution of one hundred parts of
woad, and add during the operation one part of sub-carbonate of soda, strain
the solution through silk, and add by little and little, stirring the while, a
solution of two parts of alum dissolved in eight parts of warm water. Remove
from the resulting precipitate the supernatent liquid, and filter, without any
previous washing; keep damp as before.
To obtain a precipitate of orchil: make a solution of about two hundred and
twenty pounds weight of orchil prepared for dyeing, and strain the solution
through silk, then add to it by little and little, stirring the while, a solution of
about forty-nine pounds eight ounces of alum, free from iron, in about one
hundred and four quarts, more or less, of warm water, agitate this mixture
for from five to six minutes, and then add a solution of eight and a half parts
of sub-carbonate of soda in sixteen parts of warm water. When the preci-
pitate is deposited, draw off the supernatent liquid, filter the precipitate, and
keep it damp as before.
To obtain a precipitate of cochineal: make a solution of twenty-five parts
of cochineal, strain it, add by little and little, stirring the while, a solution of
six and a quarter parts of protochloride or muriate of tin (chlorure stanneux),
and the like quantity of chloride of tin in twenty-nine parts of warm water;
draw off the supernatant liquid, filter the precipitate, without washing, and
keep it damp.
By means of one or other of these precipitates, and with the aid of the
soluble blue or indigo vat (carmin d'indigo), to be met with in commerce,
all the shades of golden yellow, of jonquil yellow, of violet, of Parma violet,
of green, and other composite or fashionable colours (couleurs de mode), may
be obtained. For example, a golden yellow may be produced by taking
about four pounds six ounces weight of a solution of gum senegal of medium
density, and about two pounds three ounces of the precipitate of fustick,
mixing the two ingredients well, and adding about an ounce and a half of
oxalic acid dissolved in a little water. Green may be produced by taking five.

page_text: pounds seven and a half ounces of the precipitate of morus tinctoria, and
dissolving therein by heat about one pound nine ounces of gum senegal, about.
six ounces and a half of alum, about two ounces of oxalic acid, then mixing
all these matters well together, and adding about five pounds seven and a half
ounces of an aqueous solution of gum senegal, and one pound one and a half
ounce of soluble blue or in ligo vat (carmin d'indigo), well levigated with an
aqueous solution of gum. Or a green of another shade may be produced by
taking about five pounds seven and a half ounces of the woad precipitate,
dissolving it in about two pounds three ounces of gum senegal, adding to it
about four and a half ounces of alum, about one ounce of oxalic acid, and
about one ounce of chloride of tin, then mixing these matters well together,
and finally adding soluble blue or indigo vat, till the particular shade desired
is obtained. Or a scarlet may be produced by taking about two pounds
three ounces of the precipitate of cochineal, mixing it intimately with about
the same quantity of warm solution of gum senegal, and then adding about
two and a quarter ounces of oxalic acid, and the like quantity of oxalate of
potash. Or, finally, a Parma violet may be produced by taking one part of an
aqueous solution of gum, and mixing it up thoroughly with the same quantity
of the precipitate of orchil. As all the coloring principles which form the
bases of these colors are insoluble, fabrics printed with them ought to be quite
damp when exposed to the influence of steam.
Fabrics printed by rollers should be exposed to the steam for from thirty-
five to forty minutes, without having been previously dried, but after having
been wound as usual on folds of dry calico; fabrics printed by hand, with one
or more colors à la Perrotine, should be first regularly and properly dried, and
then damped again by rolling them on wet calico; after this operation, the
duration of which will vary according to the nature of the fabric and the kind
of printing, the goods should be exposed to the steam for from thirty-five to
fifty minutes.
From what has been thus stated it will be seen that the great distinction
between the ordinary modes of preparing and applying the colors aforesaid,
and those herein specified, consists in this, that by the ordinary method the
coloring matters are soluble and always accompanied with brown matters
which impair their purity, and besides, as they strongly attract the damp,
but unequally, they cannot be steamed or vaporized very completely without
running by the improved method now specified, the colors being purified and
rendered insoluble by a previous preparation, the result is, that they can be
fixed uniformly by steaming; and that on account of this same insolubility, the
steaming can be effected in the presence of a great deal of water, which allows

page_text: of the operation being abridged, while a perfect combination of the colors with
the fabrics is effected.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that the improvements which
are claimed as constituting the said Invention are as follows:-
First, the mode or modes of preparing the colours aforesaid before described,
from insoluble precipitates instead of soluble extracts, which precipitates, not-
withstanding their insolubility, combine perfectly with the fabrics.
And, second, the application of the colors thus obtained to the printing of
stuffs composed of silk or wool, or of a mixture of silk and wool, by the process
of steaming (vaporisage), before the printed fabrics have been dried, or when
they have been wetted afresh after having been previously dried.
In witness whereof, I, the said Joseph Clinton Robertson, have hereunto
set my hand and seal, this Ninth day of June, in the year of our
Lord One thousand eight hundred and forty-eight.