FSN 101 Lecture Notes - Lecture 7: Maurice Ravel, Darning, Plain Weave
29 May 2018
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FSN 101 – Textiles I Lab Manual
!
Updated Aug. 24, 2016
31
Week 6 – The Plain Weave
Woven fabrics are made by interlacing two sets of yarns at right angles to each
other. The lengthwise yarns are known as warp yarns (or ends) and the
cross/widthwise yarns are known as weft yarns (or filling yarns or picks). The
lengthwise edges of the fabric are selvedges. There are three basic weaves:
plain, twill and satin. All other weaves are a variation of or combination of
these. The type of weave used in a fabric depends on the desired appearance
and performance of such factors as luster, strength, pattern, colour and cost.
Figure 11.
The plain weave is the simplest of all weaves, a simple over and under,
alternating each thread, to make a “checkerboard” pattern. It is also the strongest
of the basic weaves because the yarns are tightly interlaced. The advantage of
this weave is that very light cloth can be achieved. However, it is quite plain in
appearance.
FSN 101 – Textiles I Lab Manual
!
Updated Aug. 24, 2016
32
Part 1 – Characteristics of the Plain Weave
Objective:
To identify the difference in stretch in the warp and weft direction of a fabric.
Materials:
§ 5cm x 5cm samples of plain weave fabrics
§ linen tester/pick glass
Procedure:
Unravel a few yarns from both directions of the fabric. Lay them side by side and
examine them for differences in the number of waves or bends (crimp) which
each has. Pull on each yarn to determine if there is a difference in stretch
between the yarns of either direction. Pull on the fabric in each direction to
determine if one has more stretch than the other.
Explanation: Because of the extra tension on the warp yarns they lie straighter
in the fabric; the weft yarns develop more bends or crimp as they bend around
the more rigid warp. Also, because of the extra crimp in the weft yarns, they will
be stretchier than the warp yarns and give the overall weft direction slightly more
stretch. In an unbalanced plain weave fabric, the differences in crimp will be
something like this:
Warp:
Weft:
Results and Study Questions
1. Most garments are cut with the weft running crosswise and the warp
running lengthwise. As you have seen from the above activities, there is a
difference in the stiffness and stretchiness of the two directions. Would
you want the stretchiness to be in the lengthwise or crosswise of a
garment and why? How about the stiffness?
FSN 101 – Textiles I Lab Manual
!
Updated Aug. 24, 2016
33
2. Depending on the answer to #1 above, what is the traditional way to cut a
garment pattern and what would happen if you decided not to cut a
garment this traditional way? What happens if you cut a garment on the
bias (diagonal)?
Part 2 – Closeness of the Weave
The thread or cloth count is a way of numerically expressing the closeness of the
weave. It is usually written as two numbers (e.g. 40 x 38 meaning that there are
40 yarns per cm in the warp direction and 38 yarns per cm in the weft). The warp
count is always written first, with the X read as “by”. When fabric count is the
same for both directions, it may also be expressed merely as 80 count, with the
understanding that the fabric is a 40 x 40 count. Bed sheets are usually
described by this single number, although the number used (180, 200 etc.) is a
holdover from the Imperial system and means 90 x 90 yarns per inch.
Objective:
To determine the thread or cloth count of various fabrics
Materials:
§ Fabric sample from Part 1
§ Linen tester/pick glass
§ Darning needle
Procedure:
1. View samples with the warp direction running vertically and the weft
direction horizontally
2. If using a linen tester, place it over the sample with the calibrated edge
following the weft yarns. Don’t move it while counting the yarns. Finish
the warp count, then do the weft count. Use a darning needle as a pointer
to keep track of where you are.
3. Count the number of warp yarns in 3cm and divide by 3 for the number per
cm. This gives greater accuracy than just counting 1cm. In very close or
complicated weaves, it is easier to count yearns by unraveling a few yarns
along the edge of the fabric.
4. Record the thread count for the sample.
Document Summary
Woven fabrics are made by interlacing two sets of yarns at right angles to each other. The lengthwise yarns are known as warp yarns (or ends) and the cross/widthwise yarns are known as weft yarns (or filling yarns or picks). The lengthwise edges of the fabric are selvedges. There are three basic weaves: plain, twill and satin. All other weaves are a variation of or combination of these. The type of weave used in a fabric depends on the desired appearance and performance of such factors as luster, strength, pattern, colour and cost. The plain weave is the simplest of all weaves, a simple over and under, alternating each thread, to make a checkerboard pattern. It is also the strongest of the basic weaves because the yarns are tightly interlaced. The advantage of this weave is that very light cloth can be achieved. Part 1 characteristics of the plain weave.
