[suzeeq]

The 100gr is the weight of the skein; when we talk about weight of a yarn that's whether it's fingering, dk, worsted or bulky. Many yarns are put up in the same 100 gr skein but 100g of lace would 880 yds, sock would be 440 yds and bulky would be about 120 yds or so. So you need something that will knit to the same gauge as the original yarn, which sounds like a bulky yarn. You need the same yardage, no matter how many skeins that would take of your substitute