The method of cross stitch (English vs. Danish) and the direction in which variegated thread is stitched can have quite an impact on the way a finished piece looks. I’ve created a sample patch using 3 different threads to show the resulting patterns when variegated thread is used Vertically, Horizontally, in a Spiral and Diagonally. Those 4 columns were stitched using the English method of crossing each stitch as you go. The last column was created using the Danish method of laying all the bottom half-crosses in a row first, then coming back through that row with the top half-cross.
It is a widely accepted “rule” that you must cross each stitch as you go when using variegated threads. As shown in the last column, that’s not always the case… it just depends on the look you are going for. Stitching Danish can produce a softer appearance where you get the color differences but not quite so defined. I tend to stitch English, and I’ve gotten so used to using the variegated threads that I find myself crossing each X as I go even when using solid DMC!