Paul Rubens GUCAI Review Classical Art Chinese Painting Pigments

GUCAI Classical Art line is one of the more recent additions (late 2021) to Paul Ruben's massive and ever growing art supply catalog. Over the past 5 years they've released many art products including gum arabic based watercolors in both pro or student grade, mediums/additives, inks, papers, pastels, markers, oil paints and now Gucai. This product line is advertised as Chinese Painting Pigments, a type of water-soluble paint similar to watercolor. These have a traditional Chinese formula incorporating historical characteristics such as opacity, chalk, fugitive plant and mineral pigments and an animal gelatin binder (hide or fish glue) meant to be used for Chinese brush painting techniques on surfaces like rice paper (or Xuan paper, a bark and rice straw blend, or other bark based thin, flexible papers like mulberry).

The pearlescent pan set is made differently than the non-mica tube colors (supposedly with gum arabic instead of animal glue). The Gucai (a gansai-like xl size pan) pearlescent colors match Paul Rubens other pearlescent (smaller half pan sets), but they do not perform as well. About 1/3 of the Gucai pearlescent colors were excessively powdery, clumping, gritty, streaky and impossible to create a solid flat wash with.

Excess water and palette mixing was required to help coax the Gucai pearlescents into a somewhat smooth wash, but then it was too transparent. I also wasted too much pigment (Gucai stuck to my brushes bristles, refusing to flow off into the water).

If you're considering the Gucai pearlescent set, I recommend the half pan set in the metal tin instead (much smoother paint, better coverage, easier re-wet).

The non-mica tube set may not yet be available on Amazon. Until then all Paul Rubens products can be purchased from the company directly in the Official Paul Rubens shop on Ali Express (like an ebay or etsy shop). 

The 24 tube set is supposedly based on traditional colors (cinnabar, realgar, malachite, azurite and plants like indigo berry and garcenia) but they also use common earths (yellow ochre) in with modern pigments (Phthalo Blue, Green, Dioxazine) and very likely Ultramarine or Cobalts. There are colors labeled as Malachite, Cinnabar/Vermilion or Realgar, which appear to be either hues for the rare toxic (mercury, arsenic) pure pigments OR are mixtures with chalk to make them less granulating and more opaque. I compared Gucai's versions to the genuine mineral watercolors and you can see how they are a similar color/hue, but they lack the genuine mineral texture and and have a cloudy chalk-like matte opacity (like cheap semi transparent white pigments PW4 or PW18).

There are no English color names or pigment code numbers for easy identification of ingredients (nor can we rely on translated color names to suggest a pigment code considering the likelihood of hues/look-alikes). The writing on the color chart below is purely speculation/guesses/computer generated translations:

Poor performance when used as a watercolor paint, on watercolor paper. The tube paints are very problematic even inside the tubes (animal glue smells like burnt garbage, the pigments separate from the white chalk additive and from the binder, some tubes were hard, some were leaky). They crack and fall out of a pan, just as badly as cheap gouache. The wet washes I did on both cellulose or watercolor papers were gritty with an unpleasant texture. This disrupted smooth washes and blending, not like the gentle pattern of granulation, but rather like hard edge drying and flocculation or speckling. The matte opaque colors look very similar to common gouache paints, but are less smooth in watery transitions to transparency than pro gouache like M.Graham or Schmincke. I recommend those if you want opaque watercolors for use on watercolor paper. Gucai are intended for use on rice paper for more simple brush painting techniques, without excessive blending, layering or overworking of the cloudy chalk-like matte surface effect.

*I will be comparing these to the highest grade of Marie's Chinese Paint for traditional techniques in the future. I do not yet own the supplies to determine how well these compare to the same type of products on rice paper at this time. I can only compare them to gum arabic based watercolor and gouache paints on common papers like Cotton Arches, Bee and Cellulose Canson XL. I am not currently implying that Gucai is a bad product, but want to be clear about its limitations for those who are generally interested in them as a type of "watercolor" (water-soluble paint / re-wets from dry).

Despite the textural quirks and difficulty with blending, these definitely could be used on any absorbent surface to create art. Techniques we apply to transparent gum arabic watercolors (like paul rubens half pans, daniel smith, schmincke and most common watercolors) can be applied here - but with less ease. Just as you could use kids bargain paints to create a master piece with a careful hand, the struggle to make it work (and the uncertainty of fading due to poor lightfastness) leads me to recommend gouache instead. I'm of the opinion these paints are best used by those who are practicing Chinese brush painting techniques on rice paper and better avoided by those working on "watercolor paper" (both cellulose or cotton, as the surface sizing/coating is the major issue here).

SIMILAR ALTERNATIVES: If you are considering using Chinese paint on cellulose or cotton "watercolor paper" I would also consider similar looking paints that are designed to work better on watercolor paper (instead of traditional papers/rice/mulberry). A pro grade gouache like M.Graham, or a watercolor-gouache hybrid which has some added matte opacity in masstone, but still flows smoothly in wet washes like ShinHan Pass on Jackson's here or Mission White below may be a good option.

Smooth watercolor-like paints that use animal glue like Boku Undo's gansai or ShinHan Korean color may also be a consideration for trying traditional paints.

The 36 pearlescent (mica based metallic) dry XL pan (gansai size) set are made up of mostly the same colors as found in their watercolor half pan size sets. There were only two colors that did not match (a silver and gold), so if you already own the half pan set there is no reason to buy these aside from the ability to use larger brushes in the big pans. The gold color in the Gucai set is brighter and slightly more shiny than the half pan watercolor set, but Gucai's #9305 is nearly identical to Coliro or Finetec's "Arabic Gold" if you already own it or can buy it individually at Jackson's.

The gansai-size pans are roughly the size of 3 half pans/1.5 full pans BUT they are not fully filled (most were less than halfway filled with paint) and sadly the Gucai pigment load is lacking (fluffy clumping mica that will be used up quicker than the dense packed watercolor half pan version). The color numbers marked with "coarse" on the chart below performed particularly streaky, clumpy/gritty and hard to re-wet.

About half of these colors will be fugitive and are not ideal for professional art/to sell/long term wall display. You can see fading in the same pigments used in their half pan set below (I'll also be testing the Gucai set independently, but results won't be available for about 1 year).

Overall I can not recommend these paints over similar products on the market. For the pearlescent set I'll stick with the normal watercolor half pans from Paul Rubens when lightfastness is not a concern. If it is, then you will find in general that standard metallics (gold, silver, copper, bronze) are the most reliably lightfast (due to being iron oxide or lamp black coated mica, both are more lightfast pigments than the colorful varieties like pearlescent pinks/blues/greens). Coliro or Finetec brand offers quite a few stable mica pearlescent and metallic watercolors (Coliro/Finetec review page).

If you'd like to see swatch cards for all the paints I own that do disclose pigment codes, and compare them side by side with other brands, check out the pigment database here! All opinions are my own, I do not do paid reviews or sponsorships. I do use affiliate links. As an Amazon associate, I earn from qualifying purchases. Thank you :)