Swaddle blanket question?

my baby will be born in the spring, so I do not want to get to many swaddle blankets that might be made of a material that is TO warm, like the mico fleece ones. I think I was gonna stick with the cotton and bamboo swaddle blankets and just get maybe one microfleece just in case. but do u only really swaddle a baby for the 1st 3 - 4 months? or longer?