A typical cross stitch floss has about 6 strands of thread in it. These strands are twisted lightly and therefore can be separated easily. While most of the patterns that you get on the Internet or in the form of kits shall specify the kind of cloth and the number of floss strands that you need to take, there is a way in which you can figure it out for yourself if you need to.

The whole idea of limiting the strands or using all of them in one go depends on the size of the cross that you are creating and the largeness of the holes that are present in the fabric. If the aida fabric or plastic mesh that you are using has a large number of crosses per inch, it means that the crosses are smaller and closely packed. In such a case you should opt for a lower number of strands when you are creating the crosses. Start with three strands and see whether it looks too crowded or not. In case it still looks too crowded, you could use two strands, Going below two strands is fairly uncommon.

If the cloth has holes that are fairly far apart, you should use all the six strands of the floss in order to ensure that you get a good picture at the end of the project. This also ensures that the cloth does not peek out from behind where you should actually be seeing he pattern alone.