Flat stitch is made up of alternate stitches which fill a design area, crossing in the centre. It has similarities with fishbone stitch, but the angle is much flatter.
Flat stitch featured in Java canvas work, a canvaswork technique popular in the late 19th century (named for the canvas, rather than the island).
When reading historical stitch descriptions, please note that the term ‘flat stitch’ has been applied to lots of different stitches which to the observer’s eyes looked flat. This includes laid work and satin stitch.
In the centre of the shape to be filled, draw two curved lines from top to bottom.
Bring the needle up on the right hand side a short distance away from the central drawn lines. Make a shallow diagonal stitch across to the left hand central line and bring the needle up on the left hand side parallel to the beginning of the first stitch.
Make a second diagonal shallow stitch across to the right hand side central line, mirroring the first stitch and crossing it in the centre.
Bring the needle up on the outline of the design next to the start of the first stitch.
Take the needle down on the left hand side central line so that the thread lays next to the previous stitch, covering the background fabric.
Structure of stitch
Mrs Archibald Christie, Samplers and Stitches (1921) , p.13
Mary Thomas, Mary Thomas’s Dictionary of Embroidery Stitches (1934) , p.100
Gillian Vogelsang-Eastwood, 'Java Canvas Work', TRC Leiden (2017). Available at: https://www.trc-leiden.nl/trc-needles/regional-traditions/europe-and-north-america/embroideries/java-canvas-work (Accessed: 25 August 2021)