I'm trying to do a design with a few geometric shapes. They are relatively small; the biggest is about 3" wide and 2" high. I want to put it on a knit T-shirt. I tightened up the stitch density because the fabric was showing through, but now it's tearing the fabric and I'm getting some bobbin thread showing through. Suggestions? Satin fill? weave fill? what kind of density or stitch size??
If you are using standard 40 weight embroidery thread, stitch density of around 0.43, with underlay. Very often all you need to improve coverage is increas your underlay, not tighten the cover stitch type density.