I have bought this trim and score board by We R Memory Keepers (WRMK). My first attempt is failed, but I success the second one. I am able to figure out what is correct measure for a standard business envelope.
You need to measure by scoring at 1 3/8 inches and 10 7/8 inches width and 4 1/8 inches and 8 1/4 inches length. According to this picture, from right to left at 10 7/8 inches and 1 3/8 inches in width. For length in the same way, 8 1/4 inches and 4 1/8 inches. A real envelope is fitting to my scored paper.Two comparing envelopes. Closely perfect, huh?
I hope you will enjoy to make your own envelope with a WRMK board! I think I will enjoy my own when my remained envelopes are running out. I still have a lot of envelopes that I had bought in past! Have a fun with your project!