Have you ever found a project you love, but you don't love the yarn they use and you wonder, "Can you substitute for a different weight yarn?" The quick, one word answer is no. BUT, there are a few small instances where you can use a different weight yarn and your project will be ok.
Sunny Skies Infinity Scarf - Free crochet pattern
Can I Use A Different Weight Yarn For My Project?, 56% OFF
Stylish & Warm Free Crochet Colorwork Hat Pattern - Simply Hooked by Janet
Bernat Velvety Filet Crochet Baby Blanket, Yarnspirations
Free Infinity Scarf Crochet Patterns
Best yarn to crochet with for beginners (and the ones you should avoid)
Crochet Blanket Lovers
11 Top Yarn Choices for Crochet Blankets - Daisy Cottage Designs
Can I Use a Different Weight Yarn for My Project? - Ambassador Crochet
The Double Trouble Yarn Grey
20 FREE St. Patrick's Day Crochet Patterns - Celtic Knot Crochet