Printer: Solidoodle 2 Pro
Print time: ~9 hours
This is probably the neatest SD card holder I have. Three of the six total slots can securely hold my cards in without needing to apply much effort. One of the slots is pretty tight, requiring quite a bit of effort to insert/remove cards, while the other two are quite loose.
Of course, my results can vary with different printers, resolutions, print settings and other misc. things.
Overall, I really enjoy this and highly recommend printing it!