Honeycomb darning is a simple pulled thread stitch formed of alternating angled stitches which in combination form a honeycomb pattern.
It was evidently in use during the 19th century as it is referenced in an English Victorian pamphlet Needlework for ladies for pleasure and profit dating from 1886.
Work from right to left. Bring the needle up just inside the outline of your design. Make a vertical stitch up over four threads.
Make a holding stitch on the outline or in the border where this holding stitch will be covered later on, and then bring the needle up four threads down from the hole of the previous row.
Make a vertical stitch over four threads, taking the needle down through the hole of the previous row. Work the new row from left to right.
Structure of stitch
Various Authors, The Royal School of Needlework Book of Embroidery (2018) , p.320