Choosing quilt batting: fibers, loft, and sizing

The quick answer on size: your batting should be your quilt top plus 3–4“ on every side (more like 4–6“ if it’s going on a longarm). For a 90“ × 90“ queen top, that means at least 96“–98“ square — which is why queen packaged batting is 90“ × 108“: the length covers you, and the width is exactly the minimum.

Standard packaged batting sizes

Package	Size	Fits tops up to about
Craft	36“ × 45“	28“ × 37“
Crib	45“ × 60“	37“ × 52“
Throw	60“ × 60“	52“ × 52“
Twin	72“ × 90“	64“ × 82“
Full/Double	81“ × 96“	73“ × 88“
Queen	90“ × 108“	82“ × 100“
King	120“ × 120“	112“ × 112“

“Fits up to” is the package minus 8“ (4“ per side). If your top is within an inch or two of the limit, buy the next size — batting is the wrong place to gamble.

The fibers, honestly

Cotton is the default for good reason: it breathes, needles beautifully, shrinks ~3% to produce the classic crinkle, and gets softer with every wash. Low loft, drapes flat. Quilt lines up to the stated maximum spacing on the package (often 8“, sometimes less).

Polyester is light, lofty, inexpensive, and doesn’t shrink — the right call for tied quilts, high-loft comforters, and anything that must survive brutal washing. It can “beard” (fibers migrating through the top) with loosely woven fabrics.

Cotton/poly blends (80/20) split the difference: most of cotton’s feel with less weight and a bit more loft. The most forgiving all-rounder, and usually what longarmers recommend.

Wool is the quilter’s-quilt choice: springy, warm but breathable, shows hand and machine quilting texture better than anything else, and resists creasing when folded. Costs more; wash gently.

Bamboo/rayon blends drape softly and feel cool — lovely for summer quilts — with a price between blends and wool.

Loft, spacing, and shrinkage

• Loft is thickness. Low loft shows piecing; high loft shows quilting texture and warmth. Dense modern quilting flattens high loft anyway — pick loft for the finished look.
• Quilting distance: every batting states a maximum spacing (e.g., “quilt up to 8” apart“). Exceed it and the batting can shift and lump after washing. If in doubt, quilt denser.
• Shrinkage: cotton and blends shrink 3–5%. If you don’t prewash your fabric either, everything shrinks together at the first wash — that’s the crinkle. If you want a flat, modern finish, choose polyester or pre-shrunk batting.

Piecing leftover batting

Butt two straight edges (never overlap), then join with a wide zigzag or a whip stitch — or fusible batting tape. Keep seams parallel to the quilt’s length and away from the center where drape matters most. Pieced batting is invisible in a finished, quilted quilt; wasting half a queen package isn’t.

The free batting calculator sizes your batting from your top dimensions and preferred overhang, and tells you which package clears it.

The batting sizes chart lists every standard package alongside the largest quilt top it actually covers once you allow for overhang — worth a look before you assume a queen package fits a queen quilt.