In all these fabrics the effect is decidedly of an open or transparent nature.
In some leno fabrics the object is not to get an open effect but to get zigzag effects by crossing a thick end over a few plain ends. A simple pattern of this kind was given at Fig. 139 in dealing with leno weaving, but the effect may be varied by making the crossings at irregular intervals.
Fig. 349 is a fancy crossing in which the thick doup end is crossing over three double plain ends.
Fig. 350 is another fancy effect on the same principle. The marks on the plain ends show when these ends are lifted.
When the thick crossing ends all work in the same direction a “wave” effect is produced, which is often employed in conjunction with the “diamond” or “eye” effect, obtained from the opposite working of the two thick ends.
By using two doups a great variety of effect can be obtained. Fig. 351 shows a method much practised of making the picks bend out of a straight line. It is obvious that this will require two doups, because one doup thread has to be lifted for the first six picks, and the other doup thread does not lift until the fourth pick in the pattern.
=Check Lenos.=--Where alternate squares of leno and plain are required to be woven, it is necessary to have two doups if the leno is required to be woven four ends in a dent, with two ends crossing two, as in Fig. 352. It has been shown how a check leno or gauze can be woven with only one doup at Fig. 144, but the principle only applies to pure gauze, or one end crossing one. The draft and pegging plan for weaving a small check on the principle of Fig. 352 is given at Fig. 353, where it will be seen that eight shafts or staves are required with two doups and two slackeners.
For dobby weaving, the leno principle is chiefly used in the production of striped fabrics. One of the most popular classes of fabrics is a combination of the thick zigzag effect with an open leno effect of any kind. Fig. 354 is an example of this combined style, the stripe can either be woven with a satin or plain ground fabric.
With three doups some very elaborate effects can be obtained, but the increased cost is rather prohibitive.
A thick end can be crossed round a pair of ends weaving leno, as in Fig. 355. It is necessary to bring the end from the back stave round the doup B before crossing under the pair of leno ends, as this would make the crossing easier.