In my country , Singapore , the weather here is hot and humid which is the main reason causing my decks to be sticky . ( feels terrible ) Anyone has any suggestions on how to resolve it? Greatly appreciated .
Use a dehumidifer where you store them. If a deck is a bit warped/"thick", use a deck press if you own one, a stack of heavy books if you don't, making certain the cards are dry and "dehumidified" for a couple of days.
You should have less trouble with certain decks, such as Aladdin 1001s and Lee Asher Fournier 605s. Fourniers don't fan as well as Aladdins, but they're great for cuts and magic - and by carefully following the instructions on his site, you can actually WASH them with water, despite that they're made of paper. I'd say they resist humidity VERY well.