Thread and Yarn thickness substitutes

1-ply yarn
© F H Powell 2011

Patterns for miniature knitting and crochet often suggest yarns or threads that may not be easily obtainable to the person using the pattern. Bear in mind that fibres work up in different ways, so a pattern which states 1-ply wool may not look the same (or even be the same finished size) when knitted in 1-ply cotton or acrylic. Given the restraints of different yarns the following list gives some alternative suggestions for yarns of the same thickness, which may be used in place of the suggested yarn.
Please note: this list is not comprehensive.

Manufacturers names are included for guidance only, as many product names and thread thicknesses can be very similar.

1 strand embroidery silk/floss is equivalent to and may be replaced by:
No. 80 crochet cotton (DMC very slightly thicker)
No. 70 tatting thread (Venus, Oren Bayan)
Cotton Perle No. 12 (DMC)

1-ply yarn is equivalent to and may be replaced by:
DMC Broder Special No 25
No. 20 crochet cotton
No. 50 Oren Bayan Tatting thread
Gutermann Tacking cotton
DMC Broder Medicis (2-ply tapestry thread now discontinued by DMC)
DMC Flower thread (now discontinued)
Appletons Old English Crewel wool (2-ply tapestry thread)
No. 8 Pearl cotton (Coats/Anchor)
Cotton Perle No. 8 (DMC)
Shetland Cobweb yarns (Jamieson and Smith)

No 100 crochet cotton is equivalent to and may be replaced by:
Gutermann silk sewing thread
Sylko sewing thread (100% cotton)
1/2 ply silk thread (this is a little finer than the other threads)
Galway Linen (Texere)

No 10 crochet cotton is equivalent to and may be replaced by:
Cotton perle No 5 (DMC)
No 5 Pearl cotton (Coats/Anchor)