These mediums will provide a barrier between silk paints, allowing areas to be masked off and keeping colours isolated so that they don't bleed into each other. Apply in a solid and continuous line to prevent colours bleeding. Choose from clear gutta, which allows the colour of the silk to show through or our black or metallic coloured gutta. Clear gutta can be removed by soaking the fabric in lukewarm water for 20 minutes; black or metallic coloured gutta is permanent. Supplied in 250ml bottles or 1 litre jerry cans.