The Sweep function, which is run from the button with the vacuum on it, will remove hidden and nested stitches within designs, as well as removing hidden stitches where designs are overlapped.
These patented filters operate on the colors of a design to help reduce the stitch count, removing excessive overlays and stitches that tend to ‘ball up’ on the underside of the fabric.
Removing hidden stitches occurs as the program examines the design, looking for color layers that overlap more than is necessary for compensation. If stitches of one color layer are on top of the stitches for another color, and those stitches are not visible, they can usually be removed. Stitches that would be overlapped at the edges of the colors are important for the design so as not to have gaps, thus they are not removed. What you get is a reduction is stitch counts, a reduction in sewing time and a reduction in puckering.
Note that the Sweep is different from the process that removes stitches from overlapping designs. The Sweep operates within a single design, whereas overlapped designs are ones that are merged in separately and then laid on top of each other. The processes are similar, but different in that way. Another difference is that the Sweep filters are not temporary; they are re-run on the designs as they are adjusted (for instance by sizing.)
De-Clumping is a process where stitches within a single color are eliminated if they will gather up in small areas. These clumps of stitches can often prevent the hoop from moving freely by forming a ball under the fabric, which can anchor the needle in one area. When and if the hoop finally pulls away, the user often hears a ‘clunk’ sound and their project will probably have a gap, as registration may have been lost.
Occasionally one of the sweep filters will leave an undesirable result, which is visually evident. As a rule, these filters do a great job, and if the design looks good on the screen, it will sew nicely. However, if you see something onscreen that you don’t like, you can prevent the Sweep from running on individual colors using the Stitch Properties tab.