Hi Marta, try coating the BACK of those wings and any other delicate
parts you want preserved with a coat or two of nail polish. That
should solve your problem. Anything to be invested must be of
sufficient thickness to take it and the polish should not only
thicken, but waterproof - another essential in the investment
process. If the item can absorb the moisture during the process, it
will degrade. Good luck.
Pat Hicks