Cotton vs Acrylic vs Wool Yarn: Which One for Which Crochet Project?

Three fibers cover the vast majority of what crocheters make: cotton, acrylic and wool. They behave very differently on the hook and in use, and picking the wrong one is why a beautifully made market bag stretches to the floor, or a dishcloth felts into a puck.

Here is how they compare, and which to reach for.

Quick Comparison

• Warmth — Cotton: Low; Acrylic: Medium; Wool: High
• Breathability — Cotton: High; Acrylic: Low; Wool: High
• Stretch — Cotton: None; Acrylic: Slight; Wool: High
• Drape — Cotton: Heavy; Acrylic: Soft; Wool: Springy
• Stitch definition — Cotton: Excellent; Acrylic: Good; Wool: Good
• Machine washable — Cotton: Yes; Acrylic: Yes; Wool: Only superwash
• Pilling — Cotton: Rare; Acrylic: Common in cheap yarn; Wool: Some
• Absorbs water — Cotton: Yes, a lot; Acrylic: Barely; Wool: Yes
• Cost — Cotton: Low to medium; Acrylic: Lowest; Wool: Medium to high
• Allergy risk — Cotton: Very low; Acrylic: Very low; Wool: Some people react

Cotton

Cotton is a plant fiber with no elasticity. It is strong, absorbs water, breathes, and holds its shape until it is stretched, at which point it stays stretched.

Where cotton shines

• Dishcloths, washcloths, potholders. It absorbs, scrubs, and survives boiling washes.
• Market bags and baskets. Structure without stretch.
• Summer tops and light shawls. Cool against the skin.
• Amigurumi. The crisp stitch definition makes shaping neat, and it does not pill with handling.
• Coasters, placemats, home decor.

Where it struggles

• Warm garments. Cotton is cool, not cozy.
• Heavy blankets. A large cotton blanket is very heavy and can stretch under its own weight.
• Fitted garments that rely on stretch.
• Tight tension. With zero give, a tight cotton stitch is hard to insert the hook into.

Mercerized vs unmercerized: mercerized cotton has been treated to be smoother, shinier, and stronger, with better stitch definition. Unmercerized is softer and more absorbent. Dishcloths want unmercerized; amigurumi and home decor often look better in mercerized.

Acrylic

Acrylic is a synthetic fiber. It is cheap, light, soft when well made, machine washable, and comes in every color that exists.

Where acrylic shines

• Blankets and throws. Warm, light, washable, affordable in the quantity a blanket needs.
• Baby items. Soft and easy to wash. Check for a "baby" or "soft" line.
• Beginner projects. Forgiving of tension and cheap enough to practice on.
• Charity and gift projects where the recipient may not hand-wash.
• Items for people with wool allergies.

Where it struggles

• Breathability. Acrylic traps sweat; a summer top in acrylic is unpleasant.
• Heat. It melts. Never iron it, and never use it for potholders or trivets.
• Pilling and squeak. Cheap acrylic pills and can feel plasticky. Mid-range brands are dramatically better.
• Blocking. It does not respond to wet blocking. Steam blocking works, carefully, but it permanently relaxes the fiber, which is sometimes exactly what you want for a stiff blanket.

Wool

Wool is animal fiber, usually sheep. It is warm, elastic, breathable, and it blocks beautifully. It also felts if you wash it hot and agitate it, unless it is superwash treated.

Where wool shines

• Hats, cowls, mittens, socks. Warmth and stretch in exactly the places that need them.
• Sweaters and cardigans. Elasticity means garments recover their shape.
• Anything you will block. Lace shawls open up like nothing else.
• Felted projects on purpose: slippers, bags, bowls.

Where it struggles

• Washing. Non-superwash wool must be hand washed cold and dried flat.
• Sensitive skin. Some people itch; merino is much softer than generic wool.
• Wet items. Dishcloths in wool felt in a week.
• Cost. Good wool is pricier, and a blanket's worth adds up.
• Moths. Store it with cedar or lavender.

Blends Get You the Best of Two

• Cotton/acrylic blends are softer than cotton with more structure than acrylic; popular for baby clothes and summer garments.
• Wool/acrylic blends are warm, washable, and cheaper than pure wool; the standard choice for affordable hats and sweaters.
• Cotton/bamboo or cotton/linen blends have lovely drape for summer tops.
• Wool/nylon is sock yarn: the nylon adds durability at the heel and toe.

Project by Project

• Dishcloth — Reach for: Cotton, unmercerized
• Market bag — Reach for: Cotton or cotton/linen
• Baby blanket — Reach for: Acrylic or cotton/acrylic blend
• Chunky throw — Reach for: Acrylic or wool/acrylic
• Beanie — Reach for: Wool or wool/acrylic
• Summer top — Reach for: Cotton or cotton/bamboo
• Amigurumi — Reach for: Cotton or acrylic
• Lace shawl — Reach for: Wool or wool/silk
• Potholder — Reach for: Cotton, never acrylic
• Sweater — Reach for: Wool, wool/acrylic, or cotton/acrylic for warm climates
• Rug or basket — Reach for: Cotton, jute, or t-shirt yarn

The Test That Beats All Charts

Buy one ball, make a 15 by 15 cm swatch, wash it the way the finished item will be washed, and look at it dry. Did it stretch, shrink, pill, soften, or lose shape? That swatch tells you more than any label.