Slanted satin stitch
A series of straight parallel stitches worked at an angle across a shape to produce a smooth solid filling.
Typically used in monograming, leaves and petals.
For more background see the entry for satin stitch.
Beginning halfway along one side, bring the needle up just outside the split stitch outline. Hold the thread to set the angle of the first stitch and take the needle down accordingly, just outside the split stitch
Bring the needle up on the first side, very close to the first stitch. Make a second stitch, angling the needle towards the previous stitch and towards the split stitch
Work outwards towards the end of the shape, and then begin again in the middle. This time bring the needle up on the other side of the shape, and angle the needle towards the previous stitch as before.
Structure of stitch
Identifying Slanted satin stitch
The slanted satin stitch will have a foundation outline of split stitch, overcast by smooth, solid and parallel stitches worked at a chosen angle. The parallel stitches will be worked from one side of the shape to the other so that the outline split stitch on both sides of the shape is hidden.
Satin stitch suits smaller shapes to avoid gaping between the longer lengths of parallel stitches which may reveal the linen below.
To achieve a similar effect, larger shapes are often filled with Laid Stitch which will employ less thread.
Jacqui McDonald, RSN Essential Stitch Guides: Crewelwork (2010)
Jennifer Campbell, Ann-Marie Bakewell, Guide to Embroidery Stitches (2004) , p.114