Sources and Claims. YUPO synthetic paper is currently sold to artists by several art materials retailers, including Daniel Smith, Cheap Joe's, Dick Blick and Pearl Paint. Marketing representations vary widely. Cheap Joes's gushes that
This is one fun forgiving paper! The paint stays on top because Yupo is non-absorbent. Colors are brilliant, and they lift completely. You can paint and re-paint with no fear because if you goof, simply wipe it all off and give it another go! Lets paintings have that artsy look even if you don't feel artsy.
Daniel Smith's description is a little more professional.
Yupo is a versatile surface for work in a wide variety of media. Machine-made in the USA of 100% polypropylene, it's waterproof, stain-resistant and incredibly strong. Ideal for offset printing, silkscreen and embossing, it's also good for oils, acrylics, drawings, etchings and monotypes. No dampening or soaking is necessary before printing or painting. Watercolors run on the smooth, matte-finish surface, giving a unique fluid appearance, and mistakes can be sponged away. When the painting is finished, colors are set with a hair dryer set on low.
Finally, Legion Paper, the USA YUPO distributor, offers the product to artists because
Yupo is a unique alternative to traditional watercolor papers. It's an incredibly durable, stain-resistant, non-absorbent synthetic paper that holds ink with razor sharp precision. This extraordinary surface also resists tearing and buckling and it remains perfectly flat. Yupo's ultra white color and super smooth finish makes all the colors of the rainbow sing when applied to this revolutionary surface. Colors are brilliant, and they lift off completely. It is an extremely forgiving sheet! Neutral pH with a smooth surface.
and a corporate communication to me (February 9, 2005) from Gary Morgan at Legion Paper made the following assertions and recommendations:
Yupo is an incredibly durable, dimensionally stable synthetic paper, perhaps best known for being 100% waterproof and for its exceptionally smooth, bright white surface. Over the past several years, we've become aware that increasing numbers of amateur and professional artists are gravitating to Yupo because of its unique characteristics.
Those artists who are drawn to Yupo's other attributes, also applaud its archival qualities. More specifically, Yupo is slightly alkaline, with a pH factor ranging between 7 and 8 and is both acid and lignin free. But will it last forever?
We don't have a precise answer to that question because of our limited experience with Yupo in its relatively new roll [sic] as an artist's canvas. Nevertheless, we're quite confident that, under normal circumstances and with reasonable care and protection, "masterpieces" painted on YUPO should stand the test of time.
When you are sure your painting is finished, you should set it with a spray fixative. I recommend Delta Ceramcoat Clear Varnish or Blair #201. There are other brands, but be sure you use an acrylic product that will not yellow with time. Spray your painting outside or in a well ventilated area lightly from side to side, then up and down. Use several coats rather than one heavy coat - you do not want drips to ruin your finished work.
It's clear that the watercolor painter who wishes to use YUPO for painting has three tasks: obtaining consistent information about the sheet, understanding the bond between paint binders and polypropylene, and testing the claims for archival durability of paintings done on YUPO.
"Archival" Claims. YUPO Worldwide and its USA distributor (Legion Paper) both make the claim that YUPO is "archival" — specifically, that it is acid free and lignin free. This claim needs some context.
The standards for archival papers (see for background this article by Ivar Hoel) are intended to identify materials in a paper that can cause the paper to decompose over time. For example, lignin easily oxidizes and discolors paper, and acid can be introduced into the pulp by manufacturing processes unless the pH balance is controlled. These are two known hazards to cellulose papers.
Archival standards are
Obviously, since YUPO is made of plastic, it does not contain any wood products and acids are not used in its manufacture. So claiming that it does not is meaningless. A marketer would be literally correct to say that pig iron is all natural, nonfat, containing no artificial coloring, antibiotics or growth hormones ... but it is not really a pig and fat or growth hormones are not really relevant to describe it. You have to judge pork and pig iron, or paper and printable plastic films, by separate standards.
Painting on YUPO. there isn't much to say about painting on polypropylene plastic.
a "naive" painting on yupo
1. put the paint down and play around with it as much as you like, but once you like it leave it alone until it dries completely.
2. if you want to edit it, lift parts of it away by scrubbing gently with a moist, stiff brush and blotting the wet paint with a paper towel. if you don't like any of it, wipe it all off with a wet sponge.
do not rest your hand on the plastic, or drip water where you do not want the paint to lift.
3. you can judiciously paint over passages you have already set, but this takes some care and a very light, quick touch, otherwise you will lift the paint. use stiff brushes to create texturing effects.
4. once you have a passage you like, set the paint with a paint dryer set on warm heat or an electronic hot air gun set on very low heat. also, warming the plastic to set the second layer of paint creates a less perfect bond, because the first layer of paint interferes with the bond with the plastic.
5. liquid or honeylike paints work better than gummy or pasty paints, because the latter usually have more fillers.
watermark effects on yupo
6. chalky or coarse pigments work less well than very fine pigments, such as most synthetic organics and most iron oxides.
watermark effects on yupo
7. Finish the work by spraying with an acrylic coating or an art fixative. Frame it under glazing or cover sheet if you want to keep it.
YUPO printable plastic film
