how can you seal water soluble pencils once used?

[watches]

Hello, can anyone suggest a method or substance I could use so seal water soluble pencils on canvas without giving a varnish sheen, or requiring ironing...I have painted some canvas shoes and am looking for a method to seal them properly so I can actually wear them!
Thankyou for your help!
Lucy

[Jules001]

I know that you can buy cans of spray waterproofing, for tents and waxed jackets etc, but as I haven't used them I don't know if the spray itself would make the paintings run. I would have thought that it would need to be a spray though as anything that would need to be brushed on would smudge your design. Hope someone else can help a bit more :)

[pastafreak]

http://www.artsupplies.co.uk/item_fixative.htm