A Knitter’s Guide to Yarn
Types, Weights, and How to Choose the Right One
All skeins look pretty similar when they’re stacked like a sunset rainbow at your local yarn shop. But pick one up, and suddenly the questions roll in. Is this too heavy? Too fuzzy? Will it stretch, pill, or survive a spin in the washing machine?
Let’s untangle it all.
Choosing yarn is part science, part intuition, and part falling in love with a color you did not plan to buy. This guide walks you through yarn basics, weights, fibers, and how to read a yarn label so you can confidently choose the perfect yarn for your next coastal cast-on.
What Is Yarn, Really?
Yarn is a textile made by spinning fibers together into long strands. Those fibers can come from animals, plants, or synthetic sources. The way the fibers are spun and the number of strands twisted together (plies) affect everything from drape to stitch definition to how the yarn feels in your hands.
Fewer plies often mean a softer, loftier yarn. More plies usually give you durability and crisp stitches. Neither is better. It all depends on what you’re making.
Yarn Weight Categories Explained
Yarn weight refers to the thickness of the yarn, not how much the yarn weighs on a scale. In the U.S., yarn weights are grouped into numbered categories from lace to super bulky.
Category 0: Lace Weight
Approximate equivalent of 1 ply
The lightest of the light. Lace weight is used for delicate shawls, doilies, and airy garments. It creates stunning fabric but requires patience and gentle handling.
Best for: Lace shawls, heirloom projects
Tips: Knit slowly and avoid tight tension to prevent breakage
Categories 1, 2 & 3: Super Fine, Fine & Light
Approximate equivalent of 2 to 5 ply
These lighter yarns shine in socks, baby garments, lightweight hats, and detailed stitchwork. Sport weight, a common favorite, lives here.
Best for: Socks, gloves, baby knits
Tips: Cast on loosely and watch for splitty yarns
Category 4: Medium
Approximate equivalent of 8 to 10 ply
Often called worsted weight, this is a knitter’s best friend. It’s versatile, forgiving, and great for everything from scarves to sweaters.
Best for: Sweaters, hats, mittens, blankets
Why we love it: Excellent stitch definition and approachable for all skill levels
Categories 5 & 6: Bulky & Super Bulky
Approximate equivalent of 12 to 14 ply
These yarns mean fast projects and cozy results. Perfect when you want instant gratification or bold texture.
Best for: Chunky scarves, throws, statement knits
Tips: Knit loosely for maximum loft and softness
Common Yarn Fibers & How They Behave
Wool
A classic for a reason. Wool is warm, breathable, and easy to work with. It dyes beautifully and works year-round, depending on weight.
Care: Hand wash gently
Good to know: Can pill over time
Mohair
Soft, fluffy, and haloed with warmth. Mohair adds luxury but blurs stitch definition, making it better for simple patterns.
Care: Dry clean or gentle wash
Heads up: Can feel itchy for some knitters
Cotton
Smooth, cool, and perfect for summer knitting. Cotton shows off stitchwork but has little elasticity.
Care: Machine washable
Watch for: Yarn splitting while knitting
Cashmere
Ultra-soft and undeniably luxurious. Cashmere is warm and often blended to make it more affordable.
Care: Dry clean
Note: Prone to pilling but worth it
Angora
Incredibly soft and incredibly warm. Angora has a delicate halo and works best in simple designs.
Care: Hand wash cold or dry clean
Tip: Use textured needles for better grip
Alpaca
Warm, drapey, and hypoallergenic. Alpaca feels amazing against the skin but can stretch under its own weight.
Care: Hand wash gently
Often blended to improve structure
Silk
Smooth, shiny, and elegant. Silk adds strength and sheen, especially in blends.
Care: Hand wash or dry clean
Best for: Lace and special occasion knits
Rayon
A plant-based synthetic with incredible drape and shine. Great for warm weather garments.
Care: Check label, usually hand wash
Downside: Little elasticity and wears faster
Nylon
Strong, smooth, and durable. Often blended into sock yarns for extra longevity.
Care: Machine washable
Purpose: Strength and resilience
Polyester
Common in blends for easy care and durability. Breathable but not known for crisp stitch definition.
Care: Machine washable
Feel: Can be slightly scratchy on its own
How to Read a Yarn Label
Every yarn label is packed with useful information. Here’s what matters most:
Fiber content
Lists what the yarn is made of and in what percentages.
Weight
The thickness category of the yarn.
Yardage and weight
How much yarn you’re getting per skein.
Care instructions
Always check before committing to a project.
Suggested needle size and gauge
A starting point, not a rule.
Dye lot number
Buy skeins from the same dye lot to avoid subtle color shifts in your finished piece.
Choosing the Right Yarn for Your Project
When in doubt, ask yourself a few simple questions:
Will this be worn next to skin?
Does it need to be machine washable?
Is this for warm weather or cozy layering?
Do I want structure or drape?
A sturdy wool is perfect for winter mittens. A breezy cotton blend shines in summer tops. A fuzzy mohair scarf feels like a sea mist wrapped around your neck.
There’s no single right answer, only the yarn that fits your vision.
Trust your hands, your project, and yes, sometimes your heart. That’s part of the magic of knitting.