The 40/2 Light Weight Linen Thread is ideal for primitive stitches less than 1/4".
The 30/3 Weight linen thread is ideal for primitive stitches that are longer that 1/4". It can also be used to tie nice bows and tie on buttons for that primitive look.
The 16/2 Heavy Weight Linen Thread makes great bows, and works well for longer primitive stitches (1/2" - 3/4"). It can also be used to tie on larger buttons. Equivalent to 5 strands of embroidery floss.