I've decoupaged Rice Paper onto fabric quite easily and with good results. The example below is a long-handled tote bag, appliquéd with an A4-sized sheet from Stamperia.
Mod Podge for Fabric (the blue label pot),
a close weave fabric (cotton calico is excellent),
a brush, roller or sponge to apply the Mod Podge,
A sheet of rice paper - the example here is A4 sized,
a piece of card or a plastic bag to put inside the bag (if that's what you're decorating) to stop the mod podge from glueing the front and back of the bag (or whatever) together.
Method:
Iron your fabric to minimise creases.
Check the layout of the rice paper on the fabric - mark the corner locations lightly, in pencil, if that helps.
Cover that measured fabric surface area with a good layer of Mod Podge. Fabric Mod Podge is pretty thick - you may wish to slacken it a little with some water. It dries with a slight sheen on the fabric, so with practice you will get a tidy edge around your appliqué.
Apply the rice paper, patterned side facing up, to the Mod Podge. Do this gently, laying the rice paper down so that you can reposition it if necessary.
Smooth down the rice paper, from the middle out to the edges. Look out for creases and air bubbles; you may be able to lift the rice paper from the edge nearest to a crease or air bubble and smooth it out, but be gentle and careful.
with the flat of your hands, smooth out the rice paper on its bed of Mod Podge until you're happy it's fully adhered.
Leave the fabric somewhere clean and flat to dry overnight.
When completely dry, apply a layer of mod podge to the surface of the appliqué.
Leave, again, until it is completely dry.
The final product will have a slightly 'rubbery' feel (which I rather like). It is OK to hand wash (don't wring it out; don't dry in bright sunlight (to prevent fading)). Press under a cloth (to avoid melting your project, and to protect your iron and ironing board).
I've had a similar success using this process with napkin tissue - I'll post images and advice notes for the next session.
