I am fairly happy with my buttonholes on the whole, but there is a fundamental difference that I see with professional ones and I can't work out what I am not doing quite right.Pictured below are 1. One of mine and 2. One on a velvet Savile Row DJ I have (not made for myself sadly):The stitches seem much tighter, closer together. It's also much stiffer. The thread might also be finer I think?If I try to pull stitches tighter it just makes the hole deformed. Any ideas?