Sisal rope comes in three sizes 1/4", 3/16" and 1/8". They are light in color and very strong. I was also surprised to find how strong the 1/8" sisal is making it very versitile when the thicker sisal isn't quite thin enough for the toy you are making. Unfortunately, it does not have the uniformity in size that the 1/4" and 3/16"does.
