This is the view through my magnifying glasses when I’m working on a patch replacement. This is the minimum magnification I work at — often, I add another lens so that I’m working at 300%. It eases the eyestrain and it’s easier to take smaller stitches. Like this:
This type of patch is no fun — it has two inside corners. A common error when replacing a patch is to make a template of the patch and then cut a piece of fabric to fit. The common result is that the patch is discovered to be too small, but not until after it’s about thirty percent completed. The minute irregularities in a quilt, even across a small distance, will eat up more fabric than a straight measurement across the surface would apparently indicate.
The correct method is to use a generous swatch of fabric and lay in one side at a time, fitting and trimming as you go: