I selected the Diagonal Scotch Stitch when I encountered it as a background on one of the finished pieces we have in the shop from Needle Crossings. I thought it was a handsome background. I was concerned however that it would not prove interesting enough for the class. We've already had a class on Scotch stitch and people picked up on it right away so I was worried about devoting another hour to what is admittedly only a minor variation.
Well, I needn't have worried as my library of needlepoint books provided me with an ample supply of variations to keep the class occupied for the full hour. But first let me explain the Diagonal Scotch Stitch. Essentially it is the Scotch stitch worked on the diagonal where the smallest stitch is shared by the units. The stitch covers the canvas well and works up quickly. It will however pull the canvas out of shape so it requires the use of a frame. Also the stitch uses more thread than an "average" stitch (whatever that means).
The stitch is useful for large areas including backgrounds as it requires a medium to large area in order for the pattern to show. Large articles of clothing and tree tops look good when done in Diagonal Scotch Stitch and variegated thread.
Variations on the stitch include the use of two colors, creating diagonal stripes. One can also work a row of Continental in between each diagonal row of Scotch stitches. One of the most popular variations for the class was working the stitch over a trame thread of Kreinik braid and omitting the smallest portion of the stitch (the stitch that goes over one canvas intersection and that is shared by both units). The result is an interesting effect that looks more complicated than it is.
One final tip regarding the Diagonal Scotch stitch is to keep in mind that the longest stitch in the next row of stitches goes underneath the shortest stitch in the previous row. As long as you do this you should be in good shape. Happy stitching!