Carageenan is a natural seaweed gelling agent that provides viscosity for marbling on fabric. The carageenan solution should be mixed at least 12 hours in advance. In blender or food processor, put 1 quart of warm water and slowly sprinkle 1 teaspoon of calgon and 2 teaspoons of carageenan with blender running. Blend well and pour into tray. Make as many batches as needed until tray is filled about 1 1/2" deep.