Pure cotton can shrink a little the first time it is washed, mostly in length, especially in hot water or a tumble dryer. Mercerised cotton is generally more stable than unmercerised. To avoid surprises, knit a swatch, wash and dry it the way you will treat the finished piece, then measure again. Wash cotton garments on a gentle cycle and dry flat; cotton knits also tend to relax and lengthen slightly as they are worn.

Mercerised cotton has been treated in an alkaline bath under tension, which makes the fibre smoother, stronger and more lustrous and helps it take dye in brighter colours. It pills less and keeps its shape, but absorbs water more slowly than regular cotton. DROPS Muskat (100% mercerised cotton, 100 m per 50 g, 4 mm) and Performance Yarn Cotton Harmony (mercerised, 560 m per 100 g, 1.5 mm) are examples. Unmercerised cotton feels softer and more matte.

Yes, pure cotton gives amigurumi crisp stitch definition, a matte finish and a firm fabric that keeps its shape and does not fuzz with handling. DROPS Safran (Egyptian cotton, 160 m per 50 g, 3 mm) suits small, detailed toys, YarnArt Creative (85 m per 50 g, 4 mm hook) makes slightly larger ones, and DROPS Paris (75 m per 50 g, 5 mm) works up quickly. Use a hook a size or two smaller than suggested for a tight fabric.

Organic cotton is a popular choice for baby blankets and clothes because it is breathable, absorbent and stands up to frequent washing. Gazzal Organic Baby Cotton (100% organic cotton, 115 m per 50 g) suits light garments and small blankets, and Gazzal Sweet Baby is a bulky organic cotton (75 m per 50 g, 5–6 mm needles) that makes a thick, cosy blanket quickly. Both are OEKO-TEX certified. Note that a cotton blanket weighs more than an acrylic one of the same size.

Cotton has almost no natural elasticity and is relatively heavy, so a garment can drop in length under its own weight as you wear it. Knit at a slightly firmer gauge than you would with wool, choose finer yarns for large pieces, and add structure with seams. A fine yarn such as Alize Bella 100 (100% cotton, 360 m per 100 g) keeps a summer top light. Washing and drying flat usually brings the piece back close to its original size.

Yes, pure cotton is the classic choice for dishcloths, potholders and placemats, because it absorbs water, stands up to frequent washing and does not melt near heat the way synthetic yarns can. Unmercerised cotton is the most absorbent; mercerised cotton absorbs more slowly but looks smoother. For cloths, a light to worsted-weight cotton on 4–5 mm needles works well, such as YarnArt Creative or DROPS Paris. Avoid acrylic blends for anything that touches hot pans.