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Fig. 409. — Three-doup Net Leno Fabric, for which the Design, Draft and
Shedding Plan are given in Fig. 410.

means of their easers, to prevent undue strain upon them whilst
making a cross shed. An open shed is formed by raising front
standards (as indicated by shaded squares in the designs), with
such standard warp ends as are required, and, at the same time,
leaving doup healds down. (The object of raising a front stan-
dard heald without its corresponding doup heald is to liberate
doup warp ends so that they may return to the normal side of
their respective standard warp ends.) When a doup thread is



192



GEAMMAE OF TEXTILE DESIGN.



required at any time to pass over one or more than one pick of
weft, it must be raised for such pick or picks by means of the








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front standard and doup healds, as well as by the back standard
heald, both at the same time.



GAUZE AND LENO FABRICS. 193

§ 94. On examining the accompanying drafts it will be ob-
served that the dents of the reed are not of uniform width, and
also that some dents are left empty. It frequently becomes
necessary to remove reed wires, to obtain wider dents to receive
doup and standard warp ends — when these are in such quantity
as to prevent their free movement or passage (during shedding)
within a dent of normal width, which would chafe and break
them as the sley oscillates to and fro. Also, dents of the reed







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Fig. 411. — Three-doiip Compound Net Leno Fabric, for which the Design,
Draft and Shedding Plan are given in Fig. 412.

are sometimes left empty to permit of net doup threads spreading
in cloth, and also to accentuate the perforations characteristic
of many leno effects, as exemplified in stripes A, Fig. 407, and
stripes B, Fig. 411.

Fig. 407 illustrates an example of a two-doup net leno fabric,
of which the design, draft and shedding plan are given in Fig.
408. One set of doups are required to produce stripes A, and
another set to produce stripes B. Stripes A consist of a neat
open network, caused by the reverse drafting of six doup

13



194



GKAMMAR OF TEXTILE DESIGN.



threads, each of which crosses two taped standard warp ends.
Stripes B consist of a pair of doup threads, which cross over
twelve standard threads (taped in threes) to produce a con-
tinuous wave Hne.

Dksign (A).



Picks <




Back Standard «
Regular Heald i
Back Standard i

Plain Healds
Back Standards

Front standard
Doup

Front SUndard
Doup

Front standard
Doup



Draft (B).



Picks.

Shedding Plan (C).



Fig. 412.— Design, Draft and Shedding Plan for Compound Net Leuo
Fabric represented by Fig. 411.

Figs. 409 and 411 illustrate examples of leno fabrics, each
requiring the use of three sets of doups to produce net stripes
A, B and C respectively. That number of doups is rarely ex-
ceeded in one loom, owing to the complications to which they
give rise by the addition of numerous accessories, and the diffi-



GAUZE AND LENO FABEICS. 195

cultyiof obtaining good and clear warp sheds during weaving.
The construction of the fabric represented in Fig. 409 is clearly-
indicated in the accompanying design, draft and shedding plan
(Fig. 410), which it will well repay a student to carefully in-
vestigate.

Fig. 411 is a check leno fabric of special interest, inasmuch
ns it embodies an uncommon feature in leno weaving. This con-
sists of a compound leno effect produced by causing a thick net
doup thread to cross from side to side of other doup and standard
threads, which, combined, constitute the standard threads for
that net doup thread. By carefully examining the design, draft
and shedding plan (Fig. 412) for that cloth, and following the
operation of the healds for each pick of weft, its construction will
be easily understood. The same course should be pursued with
«ach of the preceding examples, paying special attention to the
method of drafting, and the operation of doup healds, front and
back standard healds, and easers.

Oauze and Net Leno Figuring by iVleans of Several Back
Standard Healds to each Doup Heald.

§ 95. In § 92 it was stated that, for the production of typical
net leno fabrics, as represented by the foregoing examples, the
number of doup healds, front standards and certain other es-
sential equipments of a leno loom, must necessarily correspond
with the number of different schemes of interweaving the
respective doup threads in the same fabric ; and, also, that the
number of doup healds in one loom rarely, if ever, exceeds
three. Under certain conditions, however, it is possible to
develop gauze and leno effects of a more or less ornate charac-
ter by means of only one doup heald, and one front standard,
that operate in conjunction with any practicable number of back
standard healds to govern doup warp ends, and with a corre-
sponding number of regular healds to govern standard or regular
warp ends. Or, the scope of this type of leno harness may
be increased by employing more than one doup heald, each
to operate in conjunction with a distinct set of back standard
healds of any practicable number. It is doubtful, however, if



196 GKAMMAR OF TEXTILE DESIGN.

more than two doup healds could be satisfactorily eraployed
with this arrangement of doup harness. Patterns developed
by this system are frequently so elaborate as to give the im-
pression that they have been produced by a Jacquard machine,
or of a quite impracticable number of doup healds.

Of course this system of leno weaving imposes certain limita-
tions in respect of the style or character of " douping " that are
not existent with the use of independent doup healds. For
example, all doup loarp ends must necessarily cross from the
normal or open side to the crossed side of their respective
standard warp ends simuUmieously, since they are all controlled
by the same doup heald ; but they may be raised either on the
normal or open side of standard threads, or left down (on certain
picks only) in practically any pre-determined manner. The
system also virtually demands the crossing of warp ends in
some definite and uniform manner at regular intervals of picks.
Indeed, in one variety of this class, in which single threads cross
each other to form a true gauze figure on a ground of the plain
weave, or vice versa, such conditions are inevitable ; but in
another variety, in which comparatively thick net doup threads
are introduced solely as a means of embellishment, the restric-
tions are not quite so confined.

Leno fabrics of the class under present notice are of three
distinct varieties, namely : (1) those in which a gauze figure is
surrounded by the plain or tabby weave (or vice versa), and in
which warp ends cross each other as single threads, with one
pick in each shed, as illustrated at C, Fig. 413 ; (2) those in
which either warp or weft is allowed to float freely (for the
development of brocade figuring), but which in all other respects
are like (1) ; and (3) those in which net leno figuring is de-
veloped by means of thick net doup threads upon a comparatively
light ground texture, preferably of the plain calico weave.

Although it is for many reasons (as subsequently explained in
§ 107) more expedient to weave net leno fabrics of the ordinary
type by means of a top-doup harness, that arrangement is per-
haps not so well suited as a bottom-doup harness to the produc-
tion of the class of leno fabrics under present consideration,
chiefly because the formation of a cross shed with a harness of



GAUZE AND LENO FABRICS. 197

this type would require all healds (excepting the front standard
and doup healds) to be raised. Still, when that course would
not involve excessive straining and risk of breakage of mechanical
parts, nor absorb an abnormal degree of motive power, it would
be advisable (if other circumstances were favourable), to employ
a top-doup harness in preference to a bottom-doup harness. It
should be carefully observed, however, that the accompanying
drafts and shedding plans for this variety of leno fabrics are all
arranged for bottom-doup harnesses.

§ 96. The construction of the first-named variety of this class
of fabrics is illustrated in Fig. 413, where A and B respectively
show the method of drafting and shedding to produce cloth re-
presented at C, in accordance with the design given in Fig. 414.
This is a simple pattern, repeating on twelve warp ends and picks,
developed by alternating diagonal bands of the gauze and calico
weaves, and will serve to demonstrate the principles on which
they are designed and woven.

As indicated in the draft at A (Fig. 413) warp ends are drawn
through twelve healds with a straight-over draft. After passing
through those healds in regular succession, alternate warp ends,
that are passed over an easer, are taken as doup threads (repre-
sented by white lines), which, after crossing under7ieath from
left to right of the intermediate warp ends (which become stan-
dard threads, represented by black lines), are passed through
the loose slips of the doup or half-heald which hang underneath
warp ends, as previously described and illustrated in § 90.
Thus : healds Nos. 1, 3, 5, 7, 9, 11 become back standards to
govern doup threads ; whilst healds Nos. 2, 4, 6, 8, 10, 12
are regular healds to govern standard warp ends.

§ 97. It is characteristic of this particular variety (1) of leno
fabrics that all doup threads, and those only, are invariably
raised by the front standard and doup healds for alternate (say
even-numbered) picks to form cross sheds ; but both doup and
standard threads may be raised for intermediate (or odd-numbered
picks) to form open sheds, according to the pattern required ;
care being taken not to raise, at the same time, fellow doup and
standard threads that cross each other, and pass through the
same dent of the reed. Thus, where it is required to form



198



GRAMMAR OF TEXTILE DESIGN.



Draft (A).
1 2 3 4 5 6 7 8 9 10 11 12



Shedding Plan (B).
1 2 3 4 5 6 7 8 9 10 11 12



ug Bar or Slackener t



Regular Heald 12



k Standard

Regular
k Standard

Regular
k Standard

Regular
k Standard

Regular
k Standard

Regular
k Standard

ont Standard Heald
Doup Heald



Reed nH



k No. 12 Cross Shed

11 Open „

10 Cross „

9 Open , ,

8 Cross , ,

7 Open „

6 Cross ,,

5 Open ,,

4 Cross ,,

3 Open ,,

2 Cross ,,

1 Open , ,




12 3 4 5 6



7 10 9 12 11






Fig. 413. — Graphic Diagram to demonstrate the Production of Figured Gauze and Leno Fabrics, by
means of One Doup and One Front Standard Heald operating in conjunction with more than
One Back Standard Heald. The Shedding Plan indicated at B, with the Draft A, would pro-
duce the Pattern represented in the Plan of Cloth, C, in accordance with Design Fig. 414.



GAUZE AND LENO FABKICS. 199

gauze, doup threads are raised by their respective back stan-
dards ; whilst in the calico portion standard threads are raised
by their respective healds for odd-niombered picks only. The
operation of healds in this manner gives rise to a peculiar pheno-
menon in cloth which is, at first, very puzzling to those who are
more or less intimately acquainted with leno fabrics constructed
in the usual manner. An examination of the plan of cloth will
show that doup threads appear to form an open shed when
raised on the I'ight of their respective standard threads, whereas
they are actually forming a cross shed, and vice versa. This
apparent anomaly arises in consequence of employing only one
doup heald lohich miost rise for alternate picks to develop the
plain weave in observance of the principles governing the con-
struction of these fabrics. It should also be observed (a) that
the easer must slacken doup threads whenever both front stan-
dard and doup healds are raised together to form a cross shed
— that is, on alternate picks ; and {h) that the doup heald must
lift luithout the front standard on intermediate picks. The
reason for raising the doup heald without the front standard,
when an open shed is formed, is to liberate all doup threads, and
permit of the required doup threads being raised on the normal
side of their respective standard threads by means of their back
standard healds. It will now be evident why a bottom doup
harness is preferable to a top-doup harness for weaving these
fabrics. If the latter were employed to weave design, Fig. 414,
the shedding plan B (Fig. 413), would have to be entirely re-
versed in all parts excepting the easer, and such a course would
necessitate much greater power for shedding.

The chief considerations affecting the construction of these
fabrics are clearly indicated in the plan of cloth at C, which
should be carefully studied in conjunction with the design (Fig.
414), draft at A, and shedding plan at B. This may best be
accomplished by comparing each pick in the design with the
corresponding picks in the shedding plan ; and by tracing the
lines (representing picks) from the shedding plan to the corre-
sponding picks in cloth, and thereby trace the cause to the
effect. The preparation of designs for these fabrics will be
greatly facilitated by using design or point paper on which the



200



GRAMMAR OF TEXTILE DESIGN.



narrow divisions, in one direction, are ruled off in pairs, with
lines of medium thickness, as seen in Fig. 414. The two narrow
divisions between two medium lines correspond to a doup warp
end and its fellow standard warp end that cross with each other
and pass through the same dent of the reed. Such a course
will reduce the risk of a designer inadvertently raising two
fellow warp ends at the same time, which would not be in strict





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Cross




9-


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Fig. 414.— Design for Pattern represented in Graphic Plan of Cloth, C,
Fig. 413.

accordance with the principles governing this particular variety
(1) of the class of fabrics under present consideration.

§ 98. In §§ 95 and 96 it was described how the simple gauze
and plain calico weaves could be combined to develop simple
figured effects by means of only one doup heald and a front
standard heald, operating in conjunction with several back stan-
dard and regular healds, to produce the first-named variety (1)
of this class of leno fabrics, as illustrated in Fig, 413. The
second variety (2) of this class are characterised by tuaiy-float



GAUZE AND LENO FABEICS. 201

figures on the obverse side, and weft-float figures on the re-
Terse side of cloth (when in the loom), either in combination
with the simple gauze weave only, or with both that and the
plain calico weave. It should be noted, however, that in ob-
servance of the principles governing the construction of these
fabrics, doup warp ends may only be allowed to float on that
side of their fellow standard warp ends to which they have
been crossed in the shedding harness, and not on the normal or
open side of those threads. The reason for this will be under-
stood when it is remembered that all doup warp ends must
necessarily be raised on their crossed side of standard warp ends
by means of the front standard and doup healds, for alternate
picks of weft, as required for the development of the gauze and
plain weaves ; but where warp figure is required, standard warp
ends also may be raised in those parts for the same picks. For
the intermediate picks, therefore, doup warp ends must be raised
in the float or brocade figure and gauze portions only, by means
of their respective back standard healds ; but they must be left
down in the plam weave ; also, standard warp ends must be
raised in the brocade figure and plain weave portions only, but
left doiun in the gauze portion, for the same picks. When those
picks are inserted, the doup heald is raised, in order to liberate
all doup warp ends, and permit such as are required up to be
raised by their respective back standard healds. It should be
explained, that, although doup warp ends may be raised (for the
intermediate picks) on the normal side of standard warp ends,
by means of their back standard healds, in order to develop
brocade figuring, they will not remain on that side in the cloth,
but will be pulled to the crossed side (when raised for the
alternate picks) by means of the front standard and doup healds,
and permanently remain there, as described in § 97. Doup
threads are enabled to return to their crossed side in the brocade
figure portions, in consequence of both standard and doup warp
ends being raised together in those portions, and not intersect-
ing with weft. When preparing designs for this variety of leno
fabrics, it is advisable, in order to obtain the best results, to
always separate warp figure from gauze by a margin of the
plain or cahco weave, as illustrated in the design. Fig. 415, in



202



GRAMMAR OF TEXTILE DESIGN.



which shaded squares represent the gauze weave. The shedding
plan for that design, given in Fig. 416, is adapted for a bottom -
doup harness similar to that represented in diagram Fig. 413,
but consisting of eight back standard and eight regular healds.
with a front standard and a doup heald, and an easing bar. By
studying Figs. 415 and 416 in conjunction with that diagram,
the foregoing description will be more easily comprehended. It
should be observed that these two varieties of leno fabrics impose
certain restrictions with regard tp the method of drafting warp
ends through the healds, namely : Doup and standard threads
must be arranged in the harness alternately with each other,,





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Cross Shed




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Open




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Cross „




13


Open




12
II


Cross „
Open „




10


Cross „




9


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8


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7


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Ph


6


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5


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4


Cross „




3


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Open „




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Fig. 415.— Design for Figured Gauze Fabric, for which the Shedding Plan
is given in Fig. 41(5.

and with doup threads crossing their fellow standard threads
uniformly in the same direction, when passing from their respec-
tive eyes in the back standard healds to their appointed doup
slips in the doup heald. These conditions are necessary in order
to effect the combination of true gauze with the plain or tabby
weave, which characterises these fabrics. Also, their constmc-
tion does not permit of the employment of " pointed ' or
" centred " drafts that are obtained by simply reversing in the
usual manner. This arises in consequence of w^arp ends being
in pairs, each of which consists of a doup and a standard thread
that are complementary to each other and operate in conjunction



GAUZE AND LENO FABEICS.



203



in the gauze and calico portions of the fabric, and not as in-
dependent threads.

§ 99. By far the most useful and interesting variety of this
type of figured leno fabrics is that constituting the variety (3),
in which ** net leno " figuring is developed upon a comparatively
light muslin texture, as exemplified in the accompanying repro-
ductions of cloth (Figs. 417, 419, 421 and 422). This variety
(3) of leno fabrics is of a distinctly different character from any



x6. Cross Shed

15. Open

14. Cross „

13. Open „

12. Cross

II. Open

10. Cross

9. Open

8. Cross „

7. Open „

6. Cross „

5- Open .,

4. Cross „

3. Open

2 Cross „

I. Open



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Fig. 416.— Shedding Plan for Design given in Fig. 415.



that have been previously described, and affords much greater
scope to a designer in the production of decorative effects. Also,
it imposes fewer restrictions in the construction of designs than
are imposed by the varieties of one-doup leno fabrics (1 and 2).
This arises from the employment of comparatively thick " net "
doup warp ends for figuring purposes only. These work quite
independently from the fine ground warp ends, and play no part
whatever in the construction of the foundation texture. They



204



GEAMMAE OF TEXTILE DESIGN.



may, therefore, be employed in greater or lesser numbers in
relation to ground warp ends, and may be disposed either in
groups to produce stripes (as in Fig. 417), or at regular intervals
and short distances apart, for the development of all-over
patterns. All doup warp ends are controlled by one doup heald
and a front standard heald (for the formation of cross sheds)
and such number of back standard healds (to form open sheds)
as corresponds with the different orders of interweaving doup



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Online LibraryHarry NisbetGrammar of textile design (Volume c.2) → online text (page 12 of 19)