hi everyone!

i just finished my first paper mache project - a small picture frame -- which turned out quite nice for a beginner's attempt.    i decorated it with decoupage, using Plaid Royal Coat brand glue/sealer. 

i still want to use some Renaissance gold flakes as a finishing touch in a few areas.  after that, i'll be ready to seal.  my question is, what type of sealer should i use?  the decoupage paper itself was quite thin, similar to tissue paper.  considering that and the gold flakes, should i use the Plaid brand sealer?  modge podge?  also, the gold flakes company recommends their own brand of sealer but i think they list it as being optional. 

another consideration is that the person i made this frame for lives in Asia, where its humid enough indoors to curl stationery paper left sitting in a drawer, for example.  should this affect my choice of sealer?

any suggestions would be much appreciated!  many thanks for the help!