@joer Your experience is not a singular event, so it’s relevant to share why using the sleeves could result in accidental damage to the card.
The KMC brand perfect fits are made in Japan for Japanese manufactured cards. They are a “perfect fit” for Japanese cards
Some rough dimensions:
Japanese (old back) holo: 62.7176mm wide x 0.3048mm thick
Nintendo/Pokemon holo (2010): 62.9285mm wide x 0.3302mm thick
WOTC holo: 63.0859mm wide x 0.3251mm thick
Ash, here are some sleeves I reviewed several years ago that could help. There might be some better sleeves available now. My recommendation are UP premium or penny sleeves for general use.
www.elitefourum.com/t/answered-what-are-the-best-sleeves-to-use-for-pokemon-cards/14994/1