It's just that I was trying to print onto such a size of envelope and I couldn't find it in the printer properties for resizing options. The one I used was card envelope 6 x 4 and it worked out okay, but I was just wondering.
One thing is for sure, the size of envelope exists.
Found it. For some reason it is in the US Size Guide in the Commercial section and is called 6 1/4. Don't understand why they are not in the ordinary section. Don't know why we would have them either, I'm pretty sure we don't order our envelopes from America.