I didn't think of using a small piece of paper taped to the top loader. That's a great tip. The invitation envelopes look to be the best for single cards.
Will the post office give tracking on small envelopes like that? I know for a fact that I'll want tracking on any I sell because of how much they're worth.
Thanks for the video. I still cringed at the fact he put two cards in one sleeve.
I can second Baltan that the method in the video, the paper over the top & tape over that, is perfect. I know you mentioned the tape ruining the top loader and yes that may happen. But a top loader is basically 10 cents. That is kind of its purpose, to get ruined instead of ruining the card.
I don't use normal envelopes and I don't think you can get tracking on them? Lots of the huge magic dealers do use normal envelopes to ship, since 99% of the time it is ok and they ship so much that the savings adds up to way more than the occasional mess up costs them. But there is some risk in a normal envelope method, as Baltan said, to catastrophic issues. I have seen it a few times. However, I have probably bought and sold in excess of ten thousand cards and I may have seen catastrophic issues in a normal envelope 3-4 times.
I buy bulk bubble loaders off of ebay at basically nine or ten cents each I think, by bags of 50 or so. I ship those USPS first class with free tracking and it costs me $2.60 per envelope I believe. I would rather pay a bit more for the tracking and shipping and nice envelope and know 100% I am protected. USPS can get angry about rigid things in normal envelopes since they have machine sorters, and if it gets chewed up in a normal envelope (rarely) USPS won't be sympathetic.
Typically 2 cards per sleeve is no problem. I always do 2 cards per sleeve and toploader when I sell playsets and I have never once had an issue. I would not recommend going above 2 cards though. Three can be ok with care and patience, but I never do four.