A person who used to participate here built with 18" x 3/8" strips. Using narrower strips makes a LOT of sense when they're only 1/8" thick. The narrow strips follow the curve of the hull better and reduce the amount of fairing you need to do at the joints. The downside is that it takes longer to build this way, since you have twice as many glue joints and the associated drying time compared to using 3/4" strips.

BTW, if you're going to use thin strips, you need to make up the strength and stiffness loss with more glass. The person I referred to above used 3 layers of 3.25 oz. satin weave glass.