Alternative process
AdvancedGum Print Sanguine
The soul of a Renaissance drawing
Gum Print Sanguine is our Aquaprint variant using a single pigment: natural raw sienna. One coat reveals a warm monochrome in sepia-rust tones reminiscent of Old Masters' sanguine drawings. The pre-sensitized VP gum eliminates all bichromate — safe for kitchen use.
The pictorialist heritage
Gum print (gum bichromate in its old formula) was the technique of choice for pictorialists at the turn of the 20th century. By choosing raw sienna as the pigment, one recaptures the warmth of sanguine drawings by Leonardo da Vinci. The VP kit eliminates potassium bichromate — the gum is already pre-sensitized.
Materials
640 gsm watercolour paper · Transparent gesso · VP Gum N°03 (pre-sensitized) · VP Developer N°06 · Orange Pigment N°14 or Red Ochre N°15 · Foam roller
100% non-toxic
All our chemistry is reformulated by Vision Picturale to be safe for home use. No toxic products whatsoever.
In 4 steps
How it works
Prepare
Scald the 640 gsm sheet, then apply 4 coats of transparent gesso (sizing).
Calibrate
Melt the VP gum in a bain-marie, mix in Orange Pigment N°14, apply by brush then roll with a foam roller.
Expose
Expose with the Luminograph (3 to 6 min — negative). The warm pigment requires slight overexposure.
Reveal
Develop 10 s in diluted N°06 bath, then clear in hot water (40°C) — the Renaissance drawing appears.
Frequently asked questions
Everything about this process
What is Gum Print Sanguine?
Gum Print Sanguine is the single-pigment Sienna earth variant of Aquaprint, Vision Picturale's dichromate-free reformulation of gum bichromate. The red-brown pigment evokes the sanguine chalk of Italian Renaissance preparatory drawings, used by Leonardo da Vinci and Michelangelo on tinted paper. In photography, Robert Demachy of the Photo-Club de Paris made this path famous: his red gums Primavera (1896) and Study in Red (1898) directly recall Old Master sanguine drawings. The Vision Picturale version preserves this warm sepia-rust rendering in a single separation: VP N°04 gum arabic pre-sensitized with VP N°03 Universal Sensitizer, natural Sienna earth pigment, and clearing in warm water at 40°C. The practitioner obtains a warm monochrome halfway between drawing and photography, where the brush texture remains visible and the contours breathe, without handling any CMR-classified salt at any step.
Is the Sienna earth pigment safe to use at home?
Gum Print Sanguine can be practiced in a domestic kitchen because it contains no potassium dichromate, the salt used in gum printing since 1858 and classified CMR category 1B by the European Chemicals Agency (ECHA). Sensitization relies on VP N°04 gum arabic delivered pre-sensitized with VP N°03 Universal Sensitizer, whose safety data sheet lists no carcinogenic or mutagenic pictogram. The Sienna earth pigment is a natural mineral earth, from the family of earths and oxides rated food or cosmetic grade supplied in VP kits. The VP N°06 developer is non-volatile and biodegradable. The practitioner can concretely melt the gum in a household bain-marie, clear the print in a plastic tray with warm tap water at 40°C, and dispose of wastewater through standard drains. Nitrile gloves remain recommended when mixing the powder pigment into the melted gum.
What are the steps of a Gum Print Sanguine?
A Gum Print Sanguine follows the Aquaprint protocol in a single separation. The practitioner first prepares the 640 gsm 100% cotton watercolor paper: the sheet is scalded, then sized with four coats of transparent gesso. The pre-sensitized VP N°04 gum is melted in a bain-marie and mixed with the Sienna earth pigment, typically dosed at 5 mL for an A4 sheet and supplied as Orange Pigment N°14 or Red Ochre N°15, applied by brush then evened out with a foam roller. After dark drying, exposure under a 365 nm UV-A Luminograph lasts three to six minutes: the warm pigment requires slight overexposure compared to black. Development immerses the print for ten seconds in diluted VP N°06, followed by clearing in warm water at 40°C. One or two additional layers can enrich density after two hours of drying.
Sanguine or Monochrome: which variant to choose?
Sanguine and Monochrome share the same dichromate-free Aquaprint protocol but pursue opposite visual intentions. Gum Print Monochrome seeks the density of carbon black, with a rendering close to Pictorialist charcoal drawing, ideal for portraits and still lifes. Sanguine plays instead on the transparency of red-brown: applied in two to three layers, the Sienna earth pigment enriches each pass without masking the previous one, without drifting toward pink or sepia. The warm rendering recalls Robert Demachy's prints from around 1900, including Study in Red (1898), and the sanguine drawings of the Renaissance. It is the only Vision Picturale kit that explicitly claims a graphic kinship with old master drawing. The practitioner will choose Sanguine for subjects where the warmth of the line prevails, and Monochrome for the velvety depth of black.
What skill level does Gum Print Sanguine require?
Gum Print Sanguine is accessible from advanced-beginner level, ideally after five to ten successful cyanotype prints, because it requires only one separation negative and tolerates exposure deviations of thirty seconds, unlike four-color CMYK Aquaprint which demands exposure control to within ten seconds. The Vision Picturale catalog rates the Coffret Sanguine at beginner-plus level. The variant's specific difficulty lies in exposure setting: the warm pigment requires slight overexposure, three to six minutes under the Luminograph against two to four for black. Beyond the kit, the practitioner needs 640 gsm 100% cotton watercolor paper, transparent gesso for sizing, a flat brush, a foam roller, and nitrile gloves. A hinged contact frame improves negative-to-paper contact. Fifteen to twenty single-pigment prints remain the best concrete preparation before tackling four-color CMYK registration.
How permanent is a Gum Print Sanguine print?
A Gum Print Sanguine kept in standard conditions resists for several centuries, a permanence comparable to the historic Demachy gum bichromates still visible at the Musée d'Orsay and the Metropolitan Museum of Art in New York. Demachy's sanguine gums Primavera (1896) and Study in Red (1898) attest to the stability of the red-brown pigment after more than a century. This longevity stems from the pigment itself: Sienna earth is a mineral earth rated ASTM I maximum lightfastness in Winsor & Newton or Sennelier catalogues, embedded in VP N°04 gum arabic that becomes chemically inert once hardened by exposure. No silver salt and no fugitive organic dye enters the formulation. The practitioner must mount the print on neutral pH 7 to 8.5 board and keep humidity below 60%. Standard framing behind anti-reflective glass preserves the initial density without restoration.
An alternative
Rather have it printed for you?
The artisan printmakers of Maison Picturale, a Paris atelier and gallery, produce prints in this process on commission, by hand, on 100% cotton paper. Vision Picturale supplies the kits; Maison Picturale handles the finished artwork.
Order a print at Maison PicturaleMaison Picturale · Paris 20e
