Devore or burnout describes a process of chemically destroying (and so removing) a component of a composite fabric. The technique described here refers to burning out of cellulose fibres, such as cotton, linen and rayon. Usually you use a protein/cellulose or synthetic/cellulose composite fabric.
Cellulose is decomposed by acid, and so printing on chemical salts that develop mild acids with the application of dry heat achieves this. The most commonly used chemical is sodium bisulfate, which develops mild sulphuric acid when heated.
The use of devore is not necessarily restricted solely to composite fabrics - it can be used on pure cellulose - creating holes. The edges of these can be sealed with either embroidery or machine sewing with protein or synthetic threads, or printed/painted on fabric paint - both applied before the devore is done.
If the fabric is very thick, only the surface will be in contact with the devore paste. This can be used for relief effects eg. on velvets. If the backing of the velvet is synthetic or protein, the pile can be totally removed by applying the paste to the back and so destroying the link holding the pile in.
The devore can be resisted with bicarbonate of soda or soda ash (both mild alkalis) in a thickened solution.
CHEMICALS...
DR 33 (thickener) 100g $7.00 250g $14.00
Sodium bisulfate 100g $5.00 250g $10.00 500g $18.00
Glycerine 100ml $6.00 1 litre $45.00
Silk rayon velvet (rayon pile, silk backing) white 114cm wide $42.50 per metre
INSTRUCTIONS...
MATERIALS to make 1 litre of paste
20g DR-33
small amount of methylated spirits
200g sodium bisulfate
50g glycerine
1 litre cold water
METHOD
Dissolve the sodium bisulfate in 120ml of water
Add the glycerine, and stir until dissolved. Add the rest of the water.
In a separate container - mix the DR-33 with a small amount of methylated spirit until you get a slurry
Slowly add the first solution to the DR-33 stirring all the time - it is easy to get lumps !
Leave stand for 1 - 2 hours to fully thicken.
Apply the paste to the fabric - by paint brush or stamp or screen print. Allow to dry.
Then heat with a dry iron - carefully. The moment it changes colour to biscuit - its done !
Wash in cold water to remove the burnt bits.