So how are you to figure out which ones work? I have spent a while playing with many
the ones with the powdered chalk I had issues with loss of chalk and having to play with it to get the correct amount coming down, owning several so that I can do both dark and light fabrics, Pencils I had to have a separate sharpener so that I can get a good point and the triangular one, would get broken and then I had to try to use a bit I could find...so I began to see what was out there here is my choice!

I Love this pen, it's width allows you to see the chalk and with all of the colors it gives you the ability to work on dark and light fabrics, You do need to have patience so that you do not skip your line, it is easy to break these and the carrier for the extra is flimsy, do take the time to tape one side so that it opens and shuts, or you will drop the extra chalk out!