Friday, 24 August 2012

Printing with Dyes and Paints

There are a number of thickening agents and assistants available from the George Weil website.

SILKPAINT RESIST

Silkpaint Resist is a water soluble resist which when applied to fabric, can be used as an outliner to define areas in silk painting or to block out areas to create batik effects. Dye or silk paint colours can be added to the resist to tint it. Diluted with 3 parts water, it can be painted onto fabric to help inhibit the flow of paint. Combining the resist with dye thickens the dye so that it can be used for painting or screen printing. Steam, heat set or fix dyes according to manufacturers’ instructions, machine wash on delicate cycle and iron while damp.

INDALCA PA3R

Indalca PA3R is a Guar Gum based thickener, with properties similar to Locust Bean Gum. It can be combined with dyes for painting or screen printing (1 part Indalca PA3R to 10 parts water), and as it has good stability in both strongly acidic and strongly alkaline conditions, it is recommended for use as a thickener for Disperse Dyes when heat transfer printing. Disperse dyes are for colouring synthetics such as nylon, cellulose acetate, vilene, viscose, polyester, synthetic velvets and PVC. They can also be used to colour plastic buttons and fastenings. Their effect is less potent on polyester, due to the molecular structure, allowing only pastel through to medium shades. Polyester fibre contains pores or canals within its structure which, when heated to 100°C, expand to allow particles of the dyes to enter. The expansion of the pores is limited by the heat of the water - industrial dyeing of polyester is carried out at 130°C in pressurised equipment! Full colour can be achieved when heat transfer printing with disperse dyes.

MANUTEX (SODIUM ALGINATE)

Manutex, or Sodium Alginate, is derived from seaweed and forms a viscous gum when combined with water. Manutex F is used when fine line definition is desired and for overprinting. Add 100g to 1 litre of cold water with 10g of Calgon. Add thickened water to dyes until the desired consistency is achieved. Manutex RS has a lower solid content than Manutex F and is used primarily for prints on thicker fabrics and on silk when fine definition is not required. Use 45g to 1 litre of cold water and add 10g Calgon. Calgon Water Softener helps to eliminate the effects of calcium and magnesium salts in the water which make colours weaker and duller. UREA Urea can be added to printing pastes to increase the solubility, and therefore the brightness and intensity of dyes. As a humectant it retains moisture even when dried, and this boosts the colour yield of the dye during the fixing stage. 

Although these thickeners have been used successfully with many dye products, testing before starting a project is recommended.

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