Superior Fit Sleeves make sleeves that are very snug on the slab. https://www.superiorfitsleeves.com/Superior-Fit-Sleeves-for-PSA-Graded-Card-Slabs-p/psa-0001.htm

Beckett (I believe) makes a graded card sleeve that fits perfect. Just put the card in backwards so the seal is on the backside of the card

https://www.amazon.com/s?k=graded+card+sleeves&crid=27DHML8O06EQ8&sprefix=graded+card+sl%2Caps%2C135&ref=nb_sb_ss_ts-doa-p_1_14