Have you ever noticed how, just occasionally, a narrow piece of bobbin lace will try to curl round on itself? I first noticed it many years ago with the tail of a braid lace cat motif that just wouldn't lie flat. I didn't know what the cause was bu thought that it may have been something to do with either the thread I'd used (DMC Fil á Dentelles) or with my tensioning.
Much more recently a small sample piece, to try out a new thread, did the same thing. The thread I was trying was a sample of Sulky variagated cotton, sent to me by Bev Walker in Canada, which I used as a worker with DMC Broder Machine 50. Bev suggested that maybe the DMC 50 was a bit fine for the pricking and so I worked another sample using the same pricking for DMC Broder machine 30 and Empress Mills Perle 8 cotton (chosen because it was the nearest to the Sulky that I had in my stash). Again the lace which wanted to curl, not quite as much as the finer sample but the torque was definitely there; about one full twist per 30 cm in lace that's only 1 cm wide, and pressing didn't help.
These are the lace samples - flattened in the scanner - which want to spiral.
Top; DMC Broder Machine 30 with Empress Mills Perle Cotton 8
Bottom; DMC Broder Machine 50 with Sulky Premium Mercerized Cotton 30 wt.
Bev mentioned that she had once had a problem with a snake which curled. By now I was beginning to feel fairly sure that it was the type of thread which was causing the coiling phenomenom.
Now nearly all lacemakers are familiar with Christine Sprngett's snake pattern which was originally published in her book "Lace for Children of All Ages". This is an ideal little pattern for a beginner to practice stitches or for more experienced lacemakers to try new threads or colour combinations with and so I asked Arachne members if anyone else had experienced similar problems.
Most of the replies reported no curling, but then they had used either DMC or Anchor Perle or linen threads, all of which are S-spun. All the threads used in the laces which wanted to curl were Z-spun. So I worked a few snakes myself, using a variety of threads and stiches and the result was quite conclusive.
The top picture shows what a lace snake (without his eyes!) should look like. Worked with S-spun DMC Perle 8. The lower picture is an extreme example of how much a Z-spun thread, Piper's Spun Silk 30/3, can torque the lace.
From these experiences I have concluded that spiral torquing of bobbin lace only happens when the lace is worked with Z-spun thread. All bobbin lace, apart from cloth stitch, has more twists (right over left) than crosses (left over right) and since a twist is in fact a small amount of Z spin this added to the Z-spin of the thread unbalances the whole making it want to spiral in the opposite direction. The twisting of the lace is always in the S direction.
This snake was made by Bev Walker; it too spirals quite a lot, again in the S direction. It was made with Zwicky Ursus 50 passives and Valdani 50/3 workers; both Z-spun threads.
This phenomenon seems to occur most markedly in half stitch and to a lesser extent in fairly open stitch combinations; presumably because the threads of the lace are able to move slightly. In laces with a lot of extra twists and/or the texture is very close there is less opportunity for the threads to move. One of the snake samples I worked, using Tootal Sylko which is Z-spun, was a practice Milanese braid "Figure of Eight" chosen because it has a large number extra twists to unbalance the Z-spin. It lays flat! I can only think that that is because all the twists hold the threads firmly in place and are unable to move.
So which threads are Z-spun and which are S-spun? Generally, anything which is designed primarily for machine stitching will be Z-spun whilst most cotton threads intended for hand embroidery are S-spun. Linen is nearly always S-spun (I read somewhere that this is because linen bast fibres have a natural tendency to spiral in the S direction anyway). Weaving threads may be spun in either direction and most crochet/tatting threads are double spun, ie three S-spun threads doubled in the Z-direction making a 2S-3Z thread (which does torque). Many glitter threads are of a chain or woven construction and some are metalised polyester wrapped around a filament fibre core which is not the same as spinning. The sample snake I made using a wrapped glitter thread is very stiff but lies flat.
NB: the direction of spin I refer to here is the final direction of plied/folded threads.
There is full information about which threads are S-spun and which are Z-spun in my book Threads for Lace.
Click here to see a variety of lace snakes made by myself and by some of my Arachne friends.
