Our 2-piece empty graded card slab is a great way to encapsulate your favorite card and preserve its condition. When sealing the slabs most customers use a glue applied "lightly". We recommend a glue with PMMA acrylic called Aron Alpha Type 221 available on Amazon and its not expensive. It is fast-setting typically 10-15 seconds to dry.
You have 2 additional options, you can place them in a Perfect Fit Sleeve or use a Sonic Welder like PSA, Beckett and SGC.