What Is Crochet Thread? A Guide to Thread and Sizes
If you have browsed a craft store, you may have noticed thin, tightly wound balls of what looks like string sold near the yarn, and wondered what they are. That is crochet thread, a fine material used for delicate, detailed crochet like doilies and lace. It behaves quite differently from regular yarn, and it uses special hooks. This guide explains what crochet thread is, how it is sized, and what it is used for. It is part of the crochet basics.
What Crochet Thread Is
Crochet thread is a fine, tightly twisted thread, most often made of mercerized cotton, which gives it a smooth, slightly shiny finish and crisp stitch definition. It is much thinner than the yarn used for blankets and garments, and it is designed for delicate, decorative crochet. Because it is so fine, thread is worked with tiny steel hooks and produces intricate, lightweight fabric. Think of the beautiful lace doilies your grandmother might have had, since those are classic examples of crochet thread work.
Crochet Thread vs Yarn
The main difference between crochet thread and yarn is thickness and finish. Thread is much finer and more tightly twisted, usually cotton with a smooth, crisp feel, while yarn is thicker, softer, and comes in many fibers and weights. Thread makes delicate lace and fine detail, whereas yarn makes warm, substantial fabric for blankets, garments, and toys. They are worked with different hooks and suit completely different projects. If yarn weights are new to you, our guide to yarn weights explained puts thread at the very finest end of the scale.
Understanding Thread Sizes
Crochet thread is sized by number, and here is the key thing to remember: the higher the number, the finer the thread. Common sizes include 3, 10, 20, and 30, with size 10 being one of the most popular for doilies and general thread crochet. So a size 30 thread is thinner than a size 20, which is thinner than a size 10. This can feel backward if you are used to other systems, but it is easy once you know the rule. Choosing a thread size depends on how fine and delicate you want your finished piece to be.
The Hooks You Use
Because crochet thread is so fine, it is worked with small steel hooks rather than the aluminum or plastic hooks used for yarn. Steel hooks are much thinner, and they have their own sizing system in which, like thread, higher numbers mean smaller hooks. You match the steel hook size to your thread so the stitches form neatly. These tiny hooks take a little getting used to, but they are essential for thread work. There is more on hook types and sizing in our crochet hook sizes guide.
Is Thread Good for Beginners?
Crochet thread is generally better suited to crocheters with some experience rather than complete beginners. The fine thread and tiny steel hook are harder to see and hold than chunky yarn and a large hook, and mistakes are harder to spot. For that reason, beginners are usually advised to start with smooth, medium weight yarn and a comfortable hook, as recommended in best yarn for beginners, then move on to thread once their stitches are even and confident. There is no rush, and the skills transfer directly.
What You Can Make
Crochet thread is used for delicate, decorative projects: doilies, lace, table linens, fine edgings, snowflakes, thread jewelry, and dainty appliques. Its crisp, fine nature makes it perfect for intricate, heirloom style work that would be impossible in thick yarn. Many traditional lace patterns are written for thread. If detailed, delicate crochet appeals to you, thread opens up a beautiful world of possibilities. To keep building your foundation first, explore the crochet basics and the tools covered in the beginner crochet tools guide.