I have used Sport Yarn weight (category 2) and DK light weight (category 3) yarns for doll dresses. You want to make sure the yarn is sturdy enough to be able to take on and off the doll without any problems. Here’s a link to the standard yarn weight system that you might find helpful when deciding upon what yarn to use. https://www.craftyarncouncil.com/standards/yarn-weight-system
Can baby yarn be use for these?
I have used Sport Yarn weight (category 2) and DK light weight (category 3) yarns for doll dresses. You want to make sure the yarn is sturdy enough to be able to take on and off the doll without any problems. Here’s a link to the standard yarn weight system that you might find helpful when deciding upon what yarn to use. https://www.craftyarncouncil.com/standards/yarn-weight-system