I use an 8-1/2” x 11” legal pad, each knife gets a line written in black ink. I get about 25 knives on each page, if I gift, sell, or trade a knife I write in the date and who it went to in red ink. I have one set for Buck, one set for Case, and one set for Schrade USA. Unfortunately I have never cataloged the Boker, Camillus, Utica, Victorinox, Wenger, GEC, Western, etc., so date I bought them, what I paid, where I got them, etc. is lost to me (some I remember, but many I don’t).
Ps. The Buck Knives actually get a full description on their list, three or four lines, the Case and Schrade are one line entries.