Moss can be stitched using different needle heights: lower for run around and higher for fill. In conjunction with Chain stitches, the design builds up in height from the edges to the middle. You may use different needle heights for different color areas. You may also use different needle heights for filled areas and borders. Needle height has much less effect on Chain stitches.
If you intend to use loops of various height, adjust the needle height rather than the stitch length. Even though the stitch length affects the loop height, it is easier and more accurate to adjust the needle height. See Selecting explicit needle height for details.
You can change the needle height for the stitches in the offset borders individually. For each of the offsets, select a needle height from the drop down list.