Open zigzag (pattern)

A blackwork pattern made up of columns of zigzag lines, with an added horizontal stitch at each point. It is a mid-scale pattern and is suitable for creating a geometric effect within more linear shapes.
Method
Make a horizontal stitch over two threads then bring the needle up diagonally under two intersections below and right.
Complete a back stitch into the same hole the previous stitch ends and then bring the needle up at the end of that stitch so that the thread on the back is obscured by the last surface stitch.
Repeat the last two stitches in the opposite direction.
Continue alternating from side to side to complete the column.
Each zigzag should be inline with previous columns.
Add more columns to cover the area.

Structure of stitch
Embroidery Techniques
Identifying Open zigzag (pattern)
This pattern is made of rows of zigzag stitches with a horizontal stitch extending from each point.
Each stitch is over two threads or two intersections.
References
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Various Authors, The Royal School of Needlework Book of Embroidery (2018) , p.147
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Becky Hogg, RSN Essential Stitch Guides: Blackwork (2010) , p.52