Griffin Dyeworks & Fiber Arts

Understanding Mordants and Modifiers

Tannic Acid


Description: Mordant of fine tan powder; complex glucoside of catechol and progallol found in plants.
Other Names: Acid potassium salt, catechutannic acid, common tannin, ellagic acid, ellagitannic acid, gallic acid, gallotannic acid mimotannic acid, pyrogallol, sumac tannin, tan, tanin, tannic, tannin, tannic-acid, tanningenic acid, [L] tannium
Dye Use: May be a pre-dye additive or as a final rinse; color results will be different. Adds brilliancy and fastness to some dye colors, enhances reds with tin. Mordant before using a metallic mordant (copper, iron, tin) to create a good bond with cellulose fibers. Darkens fiber with age. "Antiques" bright colors. Useful as a rinse to neutralize fibers dyed in alkaline dyebaths, such as indigo vats: use 1 tsp tannin dissolved in the rinse water. Also a tan to gray to gray-tan dye.
Best On: Especially good on silk, cellulose fibers; not good on wool
Dye Recipe: To mordant with powdered tannin: add 1 tbsp tannin to 1 lb fiber, simmer well-soaked cellulose fiber in liquid 15-20 minutes, continue with dye recipe. To mordant with plant tannin: soak tannin 24 hours, boil without fiber 1 hr, strain to remove plant pieces, add fiber, simmer 1-2 hours or as directed in dye recipe. Add 1/2 c vinegar to last rinse. For darker dye, use more tannin. Renew mordant pot with 10-15% salt, 2% soda ash, 1% Glauber's salt to weight of tannin. For blue-black color, mix tannin with iron.
Safety: Very dangerous to inhale powder! Use mask and safety goggles; do not wear contact lenses when working with tannin; if powder gets in eyes, wash eyes constantly while someone calls for medical help. California Proposition 65 Warning.
Disposal: Pour on any tree or neutralize with baking soda, pour down toilet or sink
      Oxalic acid: plants that contain tannin—all available from Griffin Dyeworks.
      Cutch (Acacia catechu): 25-35% catechutannic acid; also brown dye.
      Galls, Oak galls, Gall-nuts: Abnormal growths caused by insects; 60-78% gallic acid. Boil 1-2 hrs: 1/4 lb galls to 1 lb cotton. Turkish galls: 50-60% tannin; Chinese galls: 70% tannin
      Myrobalan (Terminalia catappa): Tropical fruit used for dye, ink; contains 25-45% ellagic acid. 2 tsp to 1 lb fiber
      Pomegranate rinds (Punica granatum): 25-45% ellagitannic acid; 2 tsp to 1 lb fiber
      Sumac (Rhus spp.): Contains 15-20% tannic acid; 1/2 lb fresh leaves and/or berries or 2 tbsp dried berries
      Tara tree (Caesalpinia spinosa, C. tinctoria): 50% tannin. Good for logwood mordant. Use 2 tsp to 1 lb fiber.
      Tea (Camellia sinensis): 1 c new or 2 c used leaves, or 5 to 8 tea bags per lb of fiber; resulting "antique" color can be used alone or over-dyed.
Source: Griffin Dyeworks for powdered tannic acid and the plant tannins, grocery store for tea

CODES: c = cup; gal = gallon; lb = pound (weight); tbsp = Tablespoon; tsp = teaspoon / [AF] Anglo-French; [Ar] Arabic; [AS] Anglo-Saxon; [Dan] Danish; [Du] Dutch; [Fr] French; [Ger] German; [Gk] Greek; [It] Italian; [L] Classical Latin; [LL] Late Latin; [ME] Middle English; [ML] Modern Latin; [OE] Old English; [OF] Old French; [ON] Old Norse; [OS] Old Saxon; [Port] Portuguese; [Sp] Spanish; [Sw] Swedish / CE = Common Era; BCE = Before Common Era

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