I’m STILL making my first project, a baby bonnet. I have to vertical seam the back. I viewed a “how to” mattress stitch seam video, but it only shows the method on garter or stockinette. It all looks neat and tidy, but when I use that technique on my seed stitch sides or ribbing, it’s really messy. The “bars” of the knits are not obvious so I end up randomly matching sides and the seam becomes very visible. In the videos the seams look invisible.
Is there any technique to use mattress stitch on different patterns, such as seed stitch, etc.?