Method for foliage and other plant material preservation and topical color application to same

A method for preserving natural plant material comprising immersion, under about 3 to 30 psig (0.21-2.1 kg/cm.sup.2 gauge) pressure, the material in ethylene glycol having a specific gravity of 1.03-1.10 for a period of 4 hours to 5 days. The material is then withdrawn, washed and dried for use or further treatment. The spent ethylene glycol is restored to its original volume with virgin ethylene glycol and re-used many times without purification. The preserved plant material is topically coated with a hydrophilic polymeric sealer optionally blended with a pigment.

BACKGROUND 
1. Field of the Invention 
This invention relates to preservation of foliage or like materials derived 
from freshly harvested plants, either under cultivation or from indigenous 
wild sources, by pressure injection with a humectant. Such materials are 
intended for decorative utilization, to be offered for sale through the 
floral trades industry. 
2. Information Disclosure Statement 
The preservation and rendering natural in appearance of various plant 
materials for decorative, scientific, or display purposes of an aesthetic 
nature have been previously described in a variety of U.S. patents. 
Various parallel but unlike claims have been offered in other U.S. 
patents. Bridgeman et al. U.S. Pat. No. 2,057,413 describes a process for 
preserving living plants, cuttings, roots, bulbs and the like by coating 
with an aqueous emulsion of carnauba wax and an oleic acid salt. 
In Dux U.S. Pat. No. 2,026,873, ruscus, already bleached and dyed, is 
softened by soaking 2-5 minutes in an emulsion of glycerin and sulphonated 
vegetable oil. 
Dux U.S. Pat. No. 2,083,191 discloses a method for bleaching and/or deying 
foliage by submerging in ethyl or methyl alcohol at elevated pressure and 
temperature. The alcohol can be used only for 4-6 batches because water 
displaced from the foliage dilutes the alcohol to below 172 proof, too 
low for proper bleaching. This is true despite replenishment of alcohol 
absorbed by the foliage. 
Korupp et al. U.S. Pat. No. 1,484,656 describes a process for producing 
decorative foliage. Cut plants are first dried, and then softened in an 
aqueous mixture of glycerin and formalin. After the plant surfaces are 
again dried, paint and/or varnish is applied to seal the glycerin within 
the treated plant. Complete pre-drying is essential to adhesion of the 
paint or varnish to the foliage. 
In Romero-Sierra et al. U.S. Pat. Nos. 4,278,715 and 4,328,256, plant 
tissues are preserved with their natural color fixed by immersion in a 
complex solution containing (a) water, (b) an alcohol exchange medium, (c) 
preservatives and (d) buffers, mordants and modifiers. 
Sheldon et al. U.S. Pat. No. 3,895,140 describes a process for preserving 
cut green foliage by extracting the normal fluids therefrom and imbibing a 
polyol, e.g. glycerin, in place thereof, at 140.degree.-250.degree. F. The 
preserved foliage may be dyed by soaking in pigment containing glycerin 
solutions. 
It has been set forth in U.S. Pat. No. 4,287,222 to Robinson that fresh 
foliage material or other plant materials of a slightly dehydrated nature 
can be preserved by the injection under pressure of humectants belonging 
to the polyol class of materials, such as glycerin, ethylene glycol, and 
various polyethylene glycols. Most specifically, its claims demand that 
the density of such humectant material should fall within the specific 
gravity range of 1.10 and 1.16. Commensurate with such preservation 
techniques is the coloring of such materials by the direct combination of 
compatible dyes with the humectant agent, which are likewise forced under 
pressure into the plant materials. Subsequently, after appropriate 
duration of treatment with both humectant and dye, the plant material is 
withdrawn, rinsed in cold water, and dried to a natural state. It has been 
our experience, in fact, in evaluating the Robinson claims that no dye, 
out of fourteen classes of dyes involving at least one hundred 
combinations of dye materials, retained the desired stay-fastness in the 
plant foliage. In our tests, the specific dyes cited in the patent failed 
to achieve the desired result. Moreover, with the exception of the basic 
green-1 class of dyes, none of the dyes was uniformly absorbed into the 
material so as to render a natural color. No dye likewise was found which 
provided in the end result a stay-fastness of any significant duration. 
Finally, under no circumstances were we able to demonstrate consistency in 
preservation which resulted in the desired natural configuration, texture 
and structural retention of foliage with any combination of 
glycerol-water. At glycerol concentrations specified in the Robinson 
patent, and even at concetrations as low as those with a specific gravity 
of 1.08, extensive swelling and rupture of the plant tissue cells was 
observed by frozen section microscopic analysis. The glycerol humectant 
subsequently escaped the foliage structure by evaporation and 
biodegradation. The so-called preserved foliage rapidly curled, dried and 
decomposed. 
SUMMARY OF THE INVENTION 
In developing alternative methods, we have observed that numerous 
mitigating factors contribute to the behavior of natural plant material, 
including foliage, under humectant pressure treatment. These include the 
freshness and development stage of foliage, the type of foliage to be 
utilized and most critical for uniform large scale preparation of 
preserved materials, the nature of the humectant. Accordingly, a present 
objective of this invention is a method for treating freshly harvested 
plant materials, specifically foliage materials, which does not entail any 
prior process of denaturing such foliage materials by bleaching, the 
addition of chemical additives, or any process other than optional 
cleaning of the foliage by simple water-surfactant wash prior to its 
preservation. Even such washing may be omitted if the foliage is free of 
any surface contaminants. The objective is to yield as an end result a 
material that has long term shelf life and long term use for decorative or 
ornamental purposes, as well as eductional, expositional, and sentimental 
purposes. More specifically, an objective is to produce a treated and 
coated materials which has a minimum shelf life of 6 months at 
60.degree.-90.degree. F. (16.degree.-32.degree. C.) and 50 percent 
relative humidity. More preferably, a shelf life of at least 1 year is 
desired. Because the prime harvest season is relatively short, foliage is 
generally treated for preservation and stored for later color application. 
Thus, the treated but unsealed and/or uncolored material will preferably 
have a shelf life of at least 4 months. However, the scope of the method 
does not require that the terminal appearance of the foliage is to be 
absolutely natural and lifelike, although the process described within 
will in fact meet such qualifications. It is possible by the present 
invention to generate foliage having virtually any color, whether natural 
or exotic in nature, dependent only on availability of the requisite 
colored coating formulation. Thus, foliage of numerous colors, as well as 
foliage having a colorless appearance, can be formulated and prepared to 
have the configuration of living foliage. The terminal objective of the 
present invention is to in fact provide a process at a high level of 
performance conducive to large scale manufacturing production of said 
materials. Whereas the mere preservation of the foliage material may not 
involve a specific dexterity related to artistic considerations, the 
coloration of the material by application of surface coatings and its 
texturing to natural color does involve the aesthetic judgement of 
artisitic color texturing. However, the materials involved in application 
of such artistic texturing are formulations of commercially available 
materials designed to achieve specific aesthetic effects. 
In summary, this invention is a method for preserving natural plant 
materials, including cut foliage, to enhance their appearance and 
decorative use. 
A batch of the plant materials is first immersed in a starting volume of 
ethylene glycol having a specific gravity of 1.03 to 1.10 at a pressure of 
about 3-30 psig (about 0.21-2.1 kg/cm.sup.2 gauge) for a period of 4 hours 
to 5 days. This range of specific gravity corresponds approximately to 
23-77 percent ethylene glycol. The plant fluids are partially exchanged 
with ethylene glycol, producing treated plant materials containing 
ethylene glycol of specific gravity 1.025-1.10. The lower value of 
specific gravity, i.e. 1.025, corresponds to approximately 19 percent 
ethylene glycol. 
The treated materials are withdrawn from the pressurized immersion in the 
spent ethylene glycol and washed to remove excess ethylene glycol from 
their surface. The materials are then dried to the touch for use or 
further treatment. 
The spent ethylene glycol is restored to its starting volume by adding 
ethylene glycol having a concentration no lower than specific gravity 
1.03. Preferably, virgin ethylene glycol is used. The restored humectant 
is re-used to treat additional batches of plant materials according to 
this process. 
The use of fungicides, bactericides, dyes, buffers, mordants and/or 
modifiers in the exchange medium is avoided. 
Following treatment with ethylene glycol, the plant materials may be 
topically coated by one of several methods. 
In one method, the materials are first dipped in a hydrophilic polymeric 
subcoating sealer. The sealed materials may then be topically tinted, if 
desired, by dip-coating or spraying with a blend of pigment in a water 
dispersible adhesive or polymeric medium. 
Alternatively, the foliage materials may be sealed and tinted in a single 
step, for example with a blend of hydrophilic polymer and pigment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
1. Preservation and Permanency Retention of Foliage Structure 
This invention comprises a method which demands as an essential 
consideration the utilization of ethylene glycol in the specific gravity 
range from 1.10 to as low as 1.03. No other humectant composition has been 
found to be suitable to meet the same quality of product as that to be 
obtained from ethylene glycol. The best results are obtained in a specific 
gravity range of 1.05-1.10, but operational product can be obtained for 
material of a specific gravity down to as low as 1.03. Optimum results, 
however, are obtained for the above specific gravity range of 1.05 to 
1.10, as measured at 20.degree. C. The exemplary preservation then 
involves the bundling of freshly cut foliage which has not been precoated 
in any way by any agent. Most specifically, prohibition is demanded 
against the utilization of any other chemical agents, such as fungicides 
or interim preservatives often utilized to coat foliage. Such materials 
should all be excluded from material to be utilized for preservation. It 
is often advantageous to remove any surface contamination of foreign 
matter, e.g. dust or dirt adhering to said foliage by a brief washing with 
cold water, with or without detergent. At the same time, however, certain 
foliages which have been desiccated to a considerable degree may likewise 
be preserved, as long as their structural integrity was retained following 
desiccation. Thus, up to about three pounds of all such foliage per gallon 
of ethylene glycol (0.36 kg per liter ethylene glycol) are inserted into a 
large immersion pressure vessel and ethylene glycol is subsequently added 
to the same vessel. Alternatively, the humectant is placed in the vessel 
first. 
To the ethylene glycol may be added an antifoaming agent in order to 
suppress foaming or gas entrainment during the pumping of ethylene glycol 
preservative-humectant in a continuous operation process. Antifoam agents 
having a silicone base are preferred, although other types may also be 
satisfactory. The antifoam agent of choice is a silicone defoamer 
manufactured by Dow-Corning Company of Midland, Mich. The specific serial 
grade and product line is Anti-Foam DB-1100A. For two hundred gallons (750 
liters) of ethylene glycol, approximately three ounces (85 grams) of the 
foaming agent is added. This need not be recharged except after extensive 
reutilization of the ethylene glycol so as to preserve foam suppression. 
In one embodiment, the immersion vessel containing ethylene glycol and 
fresh foliage is then sealed and external pressure of air or other inert 
gas is applied. 
While this method is satisfactory for some materials, most foliage species 
are more uniformly treated in a shorter time period by expressly 
eliminating gas from the pressure tank. In the absence of vigorous 
agitation, gas bubbles adhere to foliage surfaces and prevent penetration 
of humectant into the foliage. 
Therefore, in the preferred embodiment, the humectants are introduced with 
a strong flow from the bottom of the vessel to wash out all traces of 
gases clinging to the foliage surfaces and the gases entrained in the 
humectant. As the liquid flow is continued and essentially all gas bubbles 
are purged from the pressure vessel, the outflow at the top of the vessel 
is closed and hydrostatic pumping of humectant is continued until the 
desired internal pressure is achieved. Other methods of pressurizing the 
vessel may alternatively be used, provided no gas is introduced into the 
vessel, and the foliage is treated in humectant essentially free of gases. 
We have observed that for many species, elimination of gas bubbles enables 
the production of a high quality, uniformly preserved material in a much 
shorter time. For most product lines, good penetration and preservation 
with ethylene glycol is thus achieved in treatment periods as short as 4 
hours. More woody foliage and foliage having a dense structure or massive 
texture may require longer periods of pressure soaking (eight to twelve 
hours being typical). 
In addition, the elimination of entrained gas by this method also reduces 
the effects of foliage maturity and post-harvest age upon the required 
treatment time. Thus, a uniform, relatively brief treatment period may be 
used to treat a wide variety of materials without regard to such factors 
as maturity or post-harvest age. 
From a commercial standpoint, it is advantageous to minimize the processing 
time without sacrificing quality. We have found that, depending on the 
particular plant material and operating temperature, an immersion pressure 
of 3-30 psig (0.21-2.1 kg/cm.sup.2 gauge pressure) produces the best 
results in a short processing time and at the lowest cost. 
The rate of absorption of the humectant and curing of the foliage is 
directly proportional to freshness of foliage, temperature of ethylene 
glycol, and incrementally related to pressure. The specific pressure range 
is not critical per se. A minimum, however, of approximately 3 psig (0.21 
kg/cm.sup.2 gauge) to a maximum of approximately 30 psig (2.1 kg/cm.sup.2 
gauge) produces satisfactory results. In fact, the preservation and the 
humectant absorption of the foliage may be done entirely without pressure, 
but requires considerably longer duration for absorption of the humectant. 
The optimum temperature range is from 70.degree. F. (21.degree. C.) to 
approximately 105.degree. F. (41.degree. C.), and the best results are 
achieved with the freshest foliage. Light leaf foliages are readily 
preserved under such treatment for a period of 4-48 hours. Heavier wooded 
foliages, such as leather leaf fern, require a minimum of 48 hours of such 
pressure treatment. Heavy wooded foliages, leather leaf fern being a good 
example, and other examples such as heather or palms of various kinds, may 
in fact be improved in quality of natural characteristic by subsequently 
withdrawing from the pressure treatment process and soaking for an 
additional period of up to one week at atmospheric pressure in ethylene 
glycol of specific gravity 1.05 or higher. Preferably, ethylene glycol of 
specific gravity between 1.07 and 1.10 is used. During the pressure 
treatment, and during atmospheric soaking, the bulk materials are 
preferably periodically or continuously agitated in order to expel any 
adhering or entrained air-gas bubbles from the foliage matrix. This may be 
done, for example, by tipping, turning or rolling the immersion tank to 
achieve liquid movement through the foliage. 
It is most convenient to withdraw the ethylene glycol in large quantity 
from the pressure tank by an efficient surge pump. The antifoam agent will 
suppress all foaming during transfer. Likewise, loading of such tanks is 
best achieved with a high volume surge pump. During such pressure 
treatment with ethylene glycol, most of the green coloration of 
chlorophyll is lost from the foliage structure and the foliage assumes an 
off-gray to a grayish-tan coloration. 
Freshly withdrawn foliage is stacked in piles on racks from which excess 
ethylene glycol is drained into a catch tank. Subsequently, the foliage is 
washed with cold water to which has been added only a very small amount of 
a non-ionic detergent of any variety, or a blended surfactant such as 
castile soap, e.g. Lux.TM. soap. One surface adhesion of ethylene glycol 
has been removed, the foliage is shaken free of excess wetting due to 
water and hung to air dry to a state equivalent to that of natural 
non-wetted foliage. The required time for drying is inversely proportional 
to the velocity of air movement within the racked foliage. The drying time 
may be reduced by increasing air circulation through the hung foliage 
and/or by a slight elevation of temperature. Heavily structured foliage, 
such as leather leaf fern or various palms, may on occasion require a 
second washing due to a depressurizing bleed-out of the humectant ethylene 
glycol from the material. Subsequent topical coloration of the preserved 
foliage demands that the bulk of ethylene glycol be cleaned from the 
foliage surface. Therefore, the number of washings required to bring the 
foliage to a surface clean condition varies. Excessive surface ethylene 
glycol is readily apparent by appearance and feel. Strictly speaking, the 
dried foliage surface is not free of ethylene glycol. In all cases, a very 
thin layer of humectant remains at the foliage surface because of 
capillary action. 
Despite dilution with plant moisture, the ethylene glycol recovered from 
the preservation process may be reutilized in effect indefinitely witout 
any apparent degradation. The only requirement is that additional ethylene 
glycol having a specific gravity no lower than 1.03 must be added back to 
the used ethylene glycol to bring the total volume back to the starting 
quantities. Preferably, virgin ethylene glycol is used. We have observed 
reutilization of a crude batch of ethylene glycol by the incremental 
readdition of virgin ethylene glycol for over eighty consecutive 
preservation runs without loss in product quality. Thus, purification of 
the ethylene glycol, e.g. by distillation, is rarely if ever required. 
Depending on foliage, anywhere from five to fifteen percent of the 
original ethylene glycol is taken up from a batch-volume ratio of three 
pounds foliage per gallon (0.36 kg per liter). During such reuse of the 
ethylene glycol, its specific gravity rapidly falls from the initial 
starting value of 1.10 to incremental values significantly below 1.10 for 
example, to 1.07 or 1.05, or even 1.03. 
For some foliage lines it is often advantageous to allow the material to 
cure for one week to two weeks prior to its subsequent utilization. 
However, light grained foliage such as sprengeri or plumosus dry quickly 
and leave very little residual humectant and may be carried on to the 
coloration step almost immediately. 
In the event that foliage need not be colored for its end use, it may be 
utilized in its preserved form in a tannish-gray appearance It slowly 
changes over a period of four to five days from a tan gray to an amber 
brown color. If exposed to sunlight for varying durations, e.g, 20-100 
hours the coloration bleaches to a pale buckskin tan. It is the intent of 
this invention to market such tan colored foliage under the color label of 
"Buckskin." Most foliages so exposed to sunlight achieve the "Buckskin" 
coloration within a period of four to five days for an eight hour day of 
direct sunlight exposure. 
The plant material which may be processed by the above invention is most 
extensive and includes, but is not specifically limited to the following. 
However, for commercial purposes, the following bear specific note: 
sprengeri, plumosus, tree fern, ming, plumosus stringers, marsh grass and 
pepper grass are preserved in two days preservation time. Deer foot moss, 
Spanish moss, reindeer moss, and other such mosses are preserved in one 
day preservation time. Various ferns, including leather leaf fern, sword 
fern, Florida flat fern, and all other such ferns, are preserved in two to 
three days, followed by optimal results obtained from an additional weak 
of soaking in ethylene glycol at atmospheric pressure. Magnolia and 
Palmetto likewise require the same treatment as leather leaf fern. Sparkle 
berry, aspidistra, Florida huckleberry, and any other variety of 
huckleberries; ivies of all types, including large ivy, grape ivy, small 
ivy, and ivies related to the mistletoe varieties, can be treated in three 
days without additional soaking at atmospheric pressure. Florida ruscus, 
coon tie fern, West Coast huckleberry, West Coast Salal, bear grass, tipi 
fern, champas, cypress, small Florida bamboo, medium bamboo and large 
bamboo require three days preservation time without additional soaking. 
All varieites of pines, spruces and firs, including Frasier fir, Austrian 
pine, Florida shortleaf pine, white pine, black spruce, Hamilton spruce, 2 
hemlocks, and all other evergreens, require three days of treatment. The 
preceding is but a partial list of plant materials which have been 
processed successfully through the utilization of the present invention. 
Other foliages are amenable to the same process as described or with only 
minor variations. The treatment time may vary, depending on the production 
schedule and plant foliage quality. 
2. Application of Lifelike Natural Green Colorant and Other Colorants 
The desirable color and hue may be applied to the preserved plant material 
by topical-dip application of an acrylic base subcoating, followed by a 
tinting applied under pressure spraying. Alternatively, a one-step topical 
coating may be applied, saving time and expense. A wide variety of colors 
and hues may be applied without restriction to the nature of foliage. The 
critical factor in the 2-step process is that an appropriate underlayment 
is first applied to the foliage followed by a very light tinting to bring 
the foliage to the desired hue. In the case of green or natural appearance 
the formulation is subsequently described. For purposes of example, 
alternate colorations will likewise be described. The practice in general 
follows in such fashion: The plant material, such as a single leaf or 
multiple bunches of sprigs, having previously been washed of all suface 
humectant, is air dryed, generally above 70.degree. F. (21.degree. C.), to 
the touch. This material is dipped into a hydrophilic base coating which 
totally masks any underlaying color of the foliage and adheres to the 
foliage surface despite the layer of ethylene glycol. During the 
preservation process the natural chlorophyll green color of the foliage 
has been destroyed due to dehydration, chemical degradation, or photo 
fading. Once the base coating has been dip applied and dried, the primary 
color tonent is applied under pressure spray. The critical feature to be 
achieved is a coating of high integrity, high retentiveness, no tackiness, 
and luster or texture comparable to natural foliage. If alternate shades, 
colors, and hues are required, these may be achieved without intent to 
duplicate or simulate natural appearance. 
The following is an exemplary formulation for a natural chartreuse green 
foliage blend. The first to be described is the base coating which is 
applied by dip to the foliage material. This does not exclude numerous 
other possible combinations which may result in satisfactory product 
quality. The base coating achieves its filming and sealing properties from 
an acrylic-glue blend underlayment. The acrylic underlayment utilized 
within the exemplary process is manufactured by McWorter Chemical 
Corporation, Carpentersville, Ill., and marketed under the trade name of 
Aquo-Mac.TM.607 or 609 series. Likewise, the exemplary pigments utilized 
for the application of appropriate colorants are marketed by Val-Spar 
Manufacturing, Rockville, Ill., and marketed under the Tint-EZE.TM. label. 
Desired green color combinations are obtained from the four component 
listing of constituents. These include: Pthalogreen-623, Organic 
Yellow-611, Titanium White-600, and Lamp Black-691. In the subsequent 
tinting process the base media can be any variety of water dispersable 
adhesive or polymeric media which binds well to the acrylic underlayment 
and like the base coat imparts sealant properties upon the foliage. In our 
process optimal results have been obtained with one of two alternative 
materials. These include a formaldehyde based adhesive manufactured by H. 
B. Fuller Company of Minneapolis, Minn., Adhesive X-3801; or 
alternatively, an antitranspirant manufactured by Agro-K Corporation of 
Minneapolis, Minn., marketed under the label of Envy-Antitranspirant.TM.. 
The preparation of stock solutions of base colorants and tinting agent 
involve the following: 
A. Base Coating Colorant Combination--Green. 
Four cups (0.95 liter) of the Pthalogreen-623, two cups (0.47 liter) of 
Organic Yellow-611, and one cup (0.24 liter) of Titanium White-600, are 
blended with seven cups (1.656 liter) of water to form a dispersed paste. 
To this dispersed paste is mixed two gallons (7.57 liters) of the 
Aquo-Mac.TM.607 or 609. 
B. Stock Solution Base Colorant--Yellow. 
Five cups (1.18 liters) of Organic Yellow-611 is likewise blended with five 
cups (1.18 liters) of water to produce a dispersant-paste. This is 
likewise blended with two gallons (7.57 liters) of Aquo-Mac.TM.607 or 609. 
Using the above stock blends, the mixture designed as the dipping coat is 
then formulated as follows: Seven quarts (1.656 liters) of the green 
pigment stock, A, are mixed with six quarts (1.42 liters) of the yellow 
pigment stock, B, and added to two gallons (7.57 liters) of 50:50 aqueous 
Adhesive 3081, or two gallons (7.57 liters) of 50:50 aqueous 
Envy-Antitranspirant.TM.. After efficient blending the total mixture is 
then diluted with twenty gallons (75.7 liters) of methyl alcohol. This 
then constitutes the base dip material. In the event that foliage is being 
utilized which is very nonuniform in color due to the preservation 
process, or due to bleach out of background colorants due to the 
preservation process or sun exposure, trace amounts of Lamp Black-691 are 
then blended to obtain depth of tone. On most occasions, no Lamp Black 
need be added. The amounts which are added in exceptional cases constitute 
quantities in the vicinity of a tablespoon (15 mL) or less. If a heavier 
application of coating in the base coating dip process is desired, then 
lesser quantities of methanol are utilized. Likewise, lighter coverage may 
be obtained by using a higher dilution of methanol. 
The pigment toning material which is applied as a spray blend to the base 
coated foliage is prepared by utilizing one part of yellow pigment blend B 
to four parts of pure methanol. To diminish the intensity of the yellow 
and to render it more of a chartreuse green color, small amounts of the 
green pigment base A are subsequently added. Thus a typical formulation 
would involve one gallon (3.78 liter) of pigment B, four gallons (15.14 
liters) methanol, and one-half cup (0.12 liter) of pigment blend A. 
The actual application of colorant to foliage is a simple direct process. 
The foliage as individual sprigs or as loosely tied bundles is dipped into 
the base coat blend and swished through this media. Entrained or adhering 
air bubbles are so purged from the foliage surface. The foliage is then 
shaken to drain any excessive film of the colorant base coat blend and 
immediately hung to dry in an inverted or upright configuration which 
allows good passage of air provided by natural air movement or enhanced by 
fan circulation. At 70.degree. F. (21.degree. C.) and 50% relative 
humidity, the base coat dires on most foliages to a state of low-tackiness 
within five to ten minutes. An additional one-half hour of curing is 
recommended prior to subsequent toning. Toning, however, may be delayed 
indefinitely. 
In this example, the natural tone blend of yellow is applied by one of two 
methods utilizing a commercial spray painting mechanism, but may be 
obtained with any nature of air-assisted, air brush, film application 
spray gun. Thus, utilizing the blend of toner containing pigment B, 
methanol, and small amounts of pigment A, a Binks-Vantage.TM. BB-2 Gun 
fitted with a nozzle size of 0.015 inch (0.38 mm) is fed through a paint 
pot reservoir of 15-35 psig (1.05-2.45 kg/cm.sup.2 gauge) within a well 
ventilated spark-free paint booth. Individual bunches of foliage are toned 
to aesthetic standards depending upon individual bunch size and foliage 
type over two to ten second durations. Individual operators develop 
varying proficiencies of application of toner. The Binks series mechanisms 
involve a fixed paint application spray cone and operate at variable air 
assisted pressure. Alternatively, utilizing the same toner blend, an 
air-over-fluid standard paint gun with paint feed from pressure pot will 
prove functional. Any spray gun possessing variable flow and variable 
pattern parameters, and preferably having an external paint mix mechanism, 
provides satisfactory results. 
Immediately after spraying, the toned foliage bundles are laid on flat 
racks, or they can be directly hung. Within seconds after application the 
toner has dried to insignificant tackiness so that individual bundles of 
foliage or individual sprigs of foliage do not adhere to each other or 
disrupt the finish by contact. However, at 70.degree. F. (21.degree. C.) 
an additional thirty minutes of drying time on such flat racks is allowed 
prior to packaging. Alternatively, the toned foliage bundles or individual 
springs may be attached to a mobile conveyor in a heated, 110.degree. F. 
(43.degree. C.), air drying tunnel and within less than three minutes the 
material exits the tunnel, ready for packaging. Individual bundles are 
bagged in polypropylene clear bags according to shipment scale design and 
twist-tie sealed. 
As described in the above example, the coating so applied renders the 
foliage natural and lifelike in color and inhibits transpiration of 
entrained humectants. Its shelf like under the conditions of production 
are significantly improved due to the application of the base coating and 
its sealant components of adhesive or antitranspirant such as outlined 
above. Numerous other possible combinations of antitranspirants or sealing 
adhesives are feasible for this process. 
Foliage which is to be rendered bleached of color due to sun bleaching 
after preservation in ethylene glycol is likewise dipped with a sealant. 
The preferred sealant blend is a combination involving the Fuller Adhesive 
X-3801 or Agro-K Corporation Envy-Antitranspirant.TM. blended with twice 
the volume of Aquo-Mac.TM.607 or 609 Acrylic Media and subsequently 
diluted with an equal volume of water. This in turn is then diluted with 
ten parts by volume of methanol. The total milky dispersant blend is 
utilized as a dip on the buckskin line of foliage and allowed to air dry 
in identical fashion to the pigment application base coat. No additional 
colorant need be added. However, if pure white foliage is to be produced, 
such a transparent base coat is subsequently oversprayed with any variety 
of Titanium White-600 tone coatings by spray application. A typical tone 
coating by spray applications would involve a blend of one cup (0.24 
liter) of Titanium White-600 dispersed in one cup (0.24 liter) of water 
which in turn is added to one gallon (3.78 liter) of Aquo-Mac and one-half 
gallon (1.89 liter) of Antitranspirant or Adhesive 3801 and diluted with 
ten gallons (37.8 liters) of methanol. White toning is applied in similar 
fashion to that described for the application of the natural chartreuse 
green toning color. 
The above are simple examples; numerous other possible color combinations 
may be applied using various varieties and classes of pigments. Thus, for 
example, foliage may be produced of a red, pink, yellow, blue, gold, 
silver, orange or any other natural or unnatural blend of colors. 
Although the two-step process of sealing and tinting described thus far 
works well with all types of foliage materials, most foliage types may be 
effectively sealed and tinted in a single step with a hydrophilic blend of 
polymer and pigment. Other possible components may include extenders, 
dispersants, thickeners, solvents, antifoam agents and pH control agents. 
This topical coating is most easily applied as a dip-coat, but it may also 
be applied by spraying. The hydrophilic nature of the blend is most 
critical to ensure adhesion to the effectively wet foliage surface having 
ethylene glycol adhering to it. 
The following exemplary one-step Formulation A renders preserved foliage 
natural in color and general appearance, and uses a green pigment latex 
which provides uniform coverage and a depth of tone which masks all 
decolorization effects resulting from the preservation process. The 
polymer latex vehicle is used to disperse and overlay the foliage in a 
film. For this purpose, we have found that vinyl acetate/hydroxyethyl 
acrylate copolymers having an average range of molecular weights of 30,000 
to greater than 35,000 are the preferred filming agents. 
______________________________________ 
Formulation A for Latex Green Base Coat 
Range Percent 
Ingredient by Weight Function 
______________________________________ 
Chrome Green (Cr.sub.2 O.sub.3) 
10.0-30.0 Pigment 
Water Ground Mica 1.50-5.00 Extender 
Sodium Polyphosphate 
0.50-1.00 Dispersant 
Sodium Carboxymethyl Cellulose 
0.30-0.70 Thickener 
Methocel .TM. Antifoam 
0.02-0.10 Antifoam 
Ammonia (0.88 H.sub.2 O solution) 
0.01-0.07 Alkalinity 
control 
Butylacetate 2-3 Coalescing 
solvent 
Vinylacetate/Hydroxyethyl 
30.0-45.0 Film former 
Acrylate/Acrylic Acid 
45:45:10 Copolymer 
(50% solids in H.sub.2 O dispersion) 
Water 30.0-45.0 
100.00 
______________________________________ 
This formulation effectively masks the unnatural faded greyish-green 
appearance of the foliage resulting from preservation with humectant 
ethylene glycol. The chrome green pigment pleasingly matches the natural 
color of many foliages. Other pigments are used to achieve whatever tint 
is desired. 
Additional artistic effects may be obtained by further steps of spraying or 
dip-coating. 
Another example of an effective hydrophilic one-step blend is shown as 
Formulation B, which is in the form of a water latex dispersed emulsion. 
The formulation is colorless without added pigment. Pigment is added to 
the formulation to obtain coloration, and is selected to achieve the 
desired aesthetic effect in the final coated foliage materials. 
______________________________________ 
Formulation B for Latex Emulsion Base Coat- 
Colorless for Pigment Blends 
Range Percent 
Ingredient by Weight Function 
______________________________________ 
Pigment - inert and 
variable in blends 
(not part of wt %) 
Talc or 7.0-15.0 Extender 
Water ground mica 
Tamol .TM. 731 1.50-2.50 Surfactant 
(Rohm and Hass) 
Methocel .TM. Antifoam 
0.10-0.30 Antifoam 
Hydroxyethyl Cellulose 
0.20-0.50 Thickener 
Butylacetate 1.00-3.00 Coalescing Solvent 
Ammonia (0.88 H.sub.2 O 
0.02-0.07 Alkalinity Control 
Solution) 
Vinylacetate/Vinyl 
40.0-60.0 Film Former 
"Versatate" .TM. 
55:45 Copolymer 
(52% solids in H.sub.2 O 
dispersion) 
Water 25.0-40.0 
100.00 
______________________________________ 
The indicated percentage component ranges are exemplary only, and are not 
intended to be limiting. Furthermore, all of the listed components in 
Formulation A and B need not be used in a particular blend. For example, 
an alkalinity control agent is not always necessary. 
Following the application of Formulations A or b or similar blends, foliage 
may be enhanced in aesthetic effect by further steps of spraying or 
dip-coating with a wide variety of colored or clear coating materials. 
Plant materials treated according to the present invention retain the 
flexibility of their freshly cut state. The strength is retained or 
enhanced, resulting in a long shelf life and a long useful life for 
decorative, scientific or display purposes. Furthermore, dust and grime 
adhering to the plant materials as a result of storage or exposition may 
be easily removed by washing with cool or cold water, optionally 
containing a weak non-ionic detergent or castile soap, to restore the 
materials to a clean, aesthetically attractive state.