I found a triangle pulled thread stitch in an old Dutch embroidery book for my Casalguidi background. I like the shape, so I share my way of stitching it. It's stitched in rows from right to left. The stitch is done over 3 x 6 threads. First you make a V-shape in 2 steps. Make a horizontal stitch from right to left by picking up 6 threads. Then make a diagonal stitch from bottom to top.
Close the top with a last stitch to complete the triangle and bring your needle up for the next stitch. When you finished a row, just turn your work and stitch the next one.
And this is how it looks on my project. I made the rows from top to bottom and reverse. I also started to make a raised stem stitch band. I couched 3 threads of cotton and covered it with satin stitches. This little sneak peek is 1 inch wide.