I've finished another glue gel resist piece that was painted last summer. This one was painted with MX dye thickened with alginate. The fabric was not pretreated because I thought I would be painting with Setacolor Fabric Paints, but I changed my mind at the last minute.
So, I mixed up a big batch of Sodium Alginate (which I think is derived from seaweed). Just a little sprinkle mixed into some warm water will thicken up nicely in about an hour.
I mixed my dye powders with a bit of urea water till they were a pasty consistency.
To mix my colors, I poured about 1/3 cup alginate mixture into a yogurt cup, added a heaping spoonful of soda ash / baking soda and a spoonful of the dye paste. I mixed this together and everything dissolved into a nice paintable dye. After the painting was complete, I covered the whole thing with plastic and left it to batch overnight.