Double Zigzag stitch 
is a row of small stitches going forward, followed by a zigzag row of small stitches going backward, so it ends at the same point where it began.
Double Zigzag is a special stitch type, recommended for lace. A running stitch line is retraced in a zigzag pattern to create a mesh if sections are placed together. Alternatively, use this stitch type for crosshatch fill.
Double Zigzag Properties
Length
Set the Length of Double Zigzag stitch from 1 to 12mm in steps of 0.1mm.
The initial setting is 2mm.
Zigzag Width
Set the Width of the Zigzag part of the stitch from 0.2 to 6mm in steps of 0.1mm.
The initial setting is 0.6mm.
Include a Linking Stitch
Use a linking stitch between sections of Double Zigzag stitch.
Set the line as an open line or a closed line (a shape).
Use Closed Border to change an open line to a closed one, or vice versa. This allows you to create a fill area with a closed or open border (a border that runs all the way around a fill area, or only part of the way).
Insert Color Change
Insert a color change between a border line and the enclosed fill area. The Color Selection dialog is displayed.
Insert Color Change is only used when the line forms the border to a fill area.