I use tappits all the time. I cut out my letters let them dry then place them on the cake or cake board. I have only steamed them once, then let them dry and placed on the cake. Sometimes I airbrush them, let them dry then place them. I have never had any bleeding of colour. So go ahead and dust them, then steam them, let them dry, overnight a couple days, whatever works, then place them on the cake. They should be just fine. I use them on buttercream and refrigerate them all the time with no trouble or bleeding.
Hope that helps.
Teri, Ontario, Canada http://www.TeriLovesCake.ca
