If your worsted weight yarn is too thin to get 4 stitches to the inch, doubling it will make it into a bulky yarn that will be very stiff knitted at 4 to the inch. Better to add a strand of fingering weight yarn.
If your worsted weight yarn is too thin to get 4 stitches to the inch, doubling it will make it into a bulky yarn that will be very stiff knitted at 4 to the inch. Better to add a strand of fingering weight yarn.