I'm planning to lay an 8-in round of fondant over a mirror that has a raised design of a mermaid around it.  I don't have alot of time with the mirror (it's for a surprise birthday cake).  I need to know if I should add something to the fondant to make it harden quicker and keep it's shape (e.g., tylose), or use another method.  I cannot make a mold of the mirror. any help or suggestions I would really appreciate it.

hmmm

first i would make a 'mold' of aluminum foil and fill it in so the foil can be turned upside down and lay flat and retain the general shape of the mermaid

so the mermaid has a nice resting place so it hopefully will hold shape and the details good

this is all sight unsen of course by me

but yes--tylose or cornstarch so that it dries quick and crisp

i mean i made a traditional nurse's cap once  with the brim that just kinda sticks out there

i added a boatload of cornstarch and kneaded the foo out of it

the guests were coming in the door as i was setting it on the cake it had no time to set up but it did not budge

so i hope you can get it crisp enough to not loose much shape hence the foil

good luck!!!

thanks so much.