>>10256363pile them in a free USPS flat mail box, then store it somewhere at least 6 inches off the floor and in a room that stays about 60 to 80 degrees at normal humidity. That should get it.
Not letting the plastic breath and/or getting it hot is usually what fucks them up
videogame fags will tell you shit like old plastic just yellows because muh nintenders yellowed, but the most yellowed toys I've seen have all been kept in a garage or attic. Where it either gets really hot and/or humid.