I finally found a moment to share the results of the expandable paint experiments. My main interest was not to see them puff (though that's fun too!), but to see how the medium I'm using takes various colouring media. So I stamped and blobbed the expandable paint without colouring onto various fabrics, and added the colour afterwards.
These samples show the expandable paint as it was printed and after it was coloured with acrylic paint. The first sample was stamped with a square of plastic grid, rather like the plastic used to stop leaves falling into your gutters. Since the plastic strips all run the same way on one side, single stamping just gives you stripes, but turned at right angles, it give you a criss cross pattern. Once it was dry and puffed with a heat gun, I painted the whole sample with blue acrylic paint, wet on wet; I wet the fabric with water first and brushed on quite wet paint. I added a touch of Treasure Gold afterwards, once it had dried.
The second sample was stamped using a kitchen sink strainer, and dry brushed with the same paint once it had been puffed; I touched a dry brush in the paint and brushed it lightly across the surface. The paint just sits on the high points, a bit like taking a rubbing. The strainer is a fun stamping object but one of the group also found she got a very clear, sharp result from stencilling the expandable paint through the holes in the strainer.
The third sample was wet on dry - quite sloppy paint laid down just on part of the puffed areas with a brush.
I also coloured plain puffed samples with gouache, fabric paints, calligraphy ink, Dye-na-flow, marker pen, Treasure Gold, Rub 'n Buff, Shiva Paintstiks and fabric crayons...