When designs are overlapped, there may
be stitches that are hidden, which you would like to have removed. This process
is automatically done when you save a file (controllable by preferences) but you
may want to preview the results before saving. The Remove Hidden Stitches will
run the process on those stitches so that you can evaluate the result. The
result is temporary, however, so if you change anything on the design page, the
stitches will return. This happens because changing a design will almost always
regenerate its stitches.