Quilt Batting Types Explained: Cotton, Wool, Bamboo, and Polyester

Batting is the layer most quilters think least about until it's the wrong one - too warm, too flat, or shrinking unevenly after the first wash. The four most common fiber types (cotton, wool, bamboo, and polyester) behave differently enough that picking based on price alone usually backfires. Here's what actually separates them.

Cotton

100% cotton batting has low-to-medium loft, is soft, breathable, and stable under a longarm or domestic machine because it doesn't shift much while quilting - part of why it's the standard recommendation for a first quilt. Expect roughly 3-5% shrinkage after the first wash; that isn't a flaw, it's what produces the slightly crinkled, "antique" texture a lot of quilters wash their finished quilt specifically to get. If you want a perfectly flat, un-crinkled finish, cotton isn't the right choice.

Wool

Wool batting is warmer than cotton for its weight and has a noticeably softer drape, which is why it's popular for show quilts and wall hangings where drape matters more than machine-washability. It resists shrinking as long as it's dried on a cool or air setting - hot or warm drying can felt and shrink it unpredictably, so it needs gentler laundering than cotton or polyester.

Bamboo

Bamboo batting (usually blended with a small percentage of cotton for stability) is the lightest of the four, has very low loft, and is genuinely breathable in both directions - warm enough for cooler weather without overheating in summer, which makes it a common pick for baby quilts. It's also one of the more expensive options on a per-yard basis, so it's worth reserving for projects where its specific qualities matter rather than using it as a default.

Polyester

Polyester is the highest-loft, lowest-cost option and doesn't shrink at all, which makes it the go-to for puffy, decorative quilts (think show-piece wall hangings) rather than everyday bed quilts. The tradeoff is breathability - polyester doesn't wick moisture the way cotton or bamboo does, so it can sleep warmer and less comfortably than natural-fiber battings of a similar weight.

• Everyday bed quilt, want the classic crinkled look: cotton
• Show quilt or wall hanging, want soft drape: wool
• Baby quilt or warm-climate use: bamboo blend
• Decorative/puffy piece, budget-conscious: polyester