Fullness is the amount of fabric used relative to your window's width — and it's the single biggest factor in how finished your curtains look.
What the numbers mean
A 1.5x fullness uses one and a half times your window's width in fabric. A 2x fullness doubles it, and 2.5x–3x is considered very full. Higher fullness means deeper, more voluminous folds when the curtain is closed — but it also means more fabric, more weight, and a higher cost.
Matching fullness to fabric
Lightweight fabrics like sheers and voiles generally look best at 2x–2.5x fullness — they need extra volume to avoid looking thin or see-through when closed. Heavier drapery fabrics (velvet, linen blends, blackout-backed fabric) often look great at 1.5x–2x, since the fabric itself already has body and drapes well with less volume.
Matching fullness to header style
Pencil pleat and pinch pleat headers are usually cut fuller (2x–2.5x) because the pleats themselves absorb width. Eyelet (grommet) headers typically look best around 1.8x–2x — too much fullness on eyelets can make the folds look bunched rather than wave-like. Wave headers are engineered for a consistent, soft S-curve and are usually specified at a fixed fullness (around 2x) for that look to work properly.
A simple rule of thumb
If your room feels casual and you want a relaxed look, go lower (1.5x–1.8x). If you want a formal, tailored, hotel-style finish, go higher (2x–2.5x). When you're unsure, 2x is the safest starting point for most fabrics and header styles.
You can set your fullness directly in the configurator when ordering, and our Fullness & Header Style Guide has full details on every header option we offer. Still unsure? Message us on WhatsApp with your window size and fabric choice and we'll recommend a fullness.