Cutting

The first stage in the manufacture of garments is the cutting of materials into the necessary pattern shapes.
These are then joined together by means of seams to create three-dimensional garments. Where large
quantities of a garment style must be cut, a lay is created which consists of many plies of fabric spread one
above the other. From this, all the garment pieces for all the sizes that have been planned for that lay are cut.
The pattern shapes for these garments may be drawn on a paper marker placed on top of the lay, or
information as to their shape and position may be held within a computer, to be plotted similarly on a paper
marker or used to drive an automatic cutter.
The three processes involved in cutting of garment parts accurately and economically and in sufficient volume
to keep the sewing room supplied with work are:

1. The Planning, drawing, and reproduction of the marker

The Planning, drawing, and reproduction of the marker

Marker making may be broken into two parts:

1. Marker planning, or the placement of pattern pieces to meet technical requirements such as no. of pieces,
grain, etc. and the needs of material economy.

2. Material utilization, which may include drawing the marker plan directly onto fabric, drawing it onto a paper
marker by pen or automatic plotter. It is better to use a method where same marker plan can be used many
times.

Where a paper marker is used, it is normally stabilized on the top ply of the lay by stapling or by ironing so that
an adhesive backing on the paper may lightly stick to the surface of the fabric. The paper marker is cut along
with the fabric plies, and thus destroyed. Such a marker may be required for use more than once, this method
needs an economical way of duplicating to provide copies. Where marking is done directly on the fabric, it must
be repeated for each spread of fabric.

The nature of the fabric and the desired result in the finished garment

a. Pattern alignment in relation to the grain of the fabric – Pattern pieces normally carries a grain line.
When pattern pieces are laid down a piece of cloth, the grain line should lie parallel to the line of warp in a
woven fabric or the wales in the knitted fabric. When pattern pieces are laid across a piece, the grain line
should lie parallel to the weft or course direction. In bias cutting, the grain lines will be normally be at 45
degrees to the warp.

b. Symmetry and Asymmetry - Many fabrics can be turned around (through 180 degrees) and retain the
same appearance and these are designated ‘either way’ or ‘symmetrical’. In some cases, when a fabric ply
is turned around, it does not retain the same appearance, but it is acceptable to have all the pattern pieces
of a garment facing one side. These fabrics are known as ‘one way – either way’ or ‘asymmetrical’. E.g.
fabrics with a nap or pile, which is brushed in one direction, fabrics with a surface design that does not run
the same way turned around but where either direction is acceptable. Even more restricting are fabrics
 which are one way only. E.g. fabrics with a surface deign which runs one way and is acceptable one way
only.

c. The design characteristics of finished garments – The left and right sides of the garments may be
mirror images of each other, which affects the way fabric is layed.

The requirements of quality in cutting

a. While placing of pattern pieces on the fabric, some freedom of knife movement has to be given on curves &
turns in order to get accurate cutting.

b. A pattern count must be made at the completion of the planning of marker to check that the complete menu
of patterns has been included.

c. Correct labeling of cut garment parts is essential while sorting and bundling a multi size lay after cutting.

The requirements of production planning

a. Size ratios – When an order is placed for a quantity of garments, it normally specifies a quantity of each
size and colour, the former often given as a ratio. E.g. a common ratio often used for sizes S, M, L, & XL is
1:2::2:1.

b. The requirements of production planning and control will be to supply the sewing room with an adequate
amount of cut garments at sufficiently frequent intervals, consistent with availability of fabric and the best
utilization of cutting room resources. Among the latter considerations are that for a given quantity of
garments, a high lay rather then a low lay gives a lower cutting labour cost per garment.

c. The mixing of sizes in a marker, as opposed to cutting single sizes at a time, is termed scrambling and, up
to a point, the more sizes that are included in a marker, the greater is the scope for fabric savings.

d. Efficiency of marker plan - The efficiency of a marker is calculated by a formula:

The spreading of the fabric to form a lay

The objective of spreading is to place the number of plies of fabric that the production planning process has
dictated, to the length of marker plan, in the colours required, correctly aligned as to length and width, and
without tension.

The requirements of spreading process

1. Shade sorting of cloth pieces – Lays commonly require more than one roll of fabric to achieve enough
plies in total. It is likely that cloth pieces that are same colour wont have an exact shade match. A garment
made from parts cut from these different pieces would be likely to show a shaded effect between its
different panels. Thus when deliveries of s number of rolls of cloths of the same colour are received, they
should be sorted into batches such that shade differences between them are undetectable.
2. Correct ply direction and adequate lay stability – The various types of fabrics, in terms of surface
direction, that are available, designated either way, one way – either way or one way only, have been
described above. For one way-either way, and one way only fabrics, where the pattern pieces have been
positioned in a particular direction in the marker plan, it is essential that the fabric is spread in a way that
maintains that direction.

3. Alignment of ply – Every ply should comprise at least the length and width of the marker plan, but should
have the minimum possible extra outside those measurements.

4. The nature of textile material is such that the pieces of fabric as delivered from suppliers, vary in width,
both from piece to piece and to lesser extent within single pieces. The marker plan is made to fit the
narrowest width. The surplus width of the fabric is distributed outside the edge of the marker plan. In
addition, the ends of the plies must be cut off squarely, allowing the smallest possible loss at both ends.

5. Correct ply tension – If the plies are spread with too slack a tension they will lie in ridges with irregular
fullness. If plies are spread in a stretched state they will maintain their tension while held in the lay, but will
contract after cutting or during sewing, thus shrinking the garment parts to a smaller size than the pattern
pieces. In addition to this, there are likely to be tensions inherent in the fabric roll arising from the twist,
texturising or elasticity of the yarn. These elements of stretch do not allow rapid relaxation and recovery.
Hence, the fabric in some cases may be required to be unrolled and allowed to relax overnight before
spreading.

6. Elimination of fabric faults – Fabric faults may be detected during examination of the fabric by the
garment manufacturer prior to spreading. It is possible that the spreading operator may also faults missed
in previous examination. These faults have to be marked with a tag or a strip of paper in spreading stage in
a way that they can be identified after cutting and the faulty parts be changed.

7. Avoidance of distortion in the spread – A layer of glazed paper, laid glazed side down, is normally
placed at the bottom of the spread. This helps to avoid disturbing the lowest plies of material in the spread
when the base plate of a straight knife passes underneath, and also gives stability to the lay if it is to be
moved on a floatation table.

The cutting of the fabric

The objective of cutting is to separate fabric parts as replicas of the pattern pieces in the marker plan. In
achieving this objective, certain requirements must be fulfilled:

1. Precision of cut – Garments cannot be assembled satisfactorily, and they may not fit the body correctly, if
they have not been cut accurately to the pattern shape. In manual cutting using a knife, accuracy of cut
depends on appropriate, well-maintained cutting knives and on the skill and motivation of the cutter. In both
die cutting and computer-controlled cutting, the achievement of accuracy comes from the equipment.

2. Clean edges – The raw edge of the fabric should not show fraying or snagging. Such defects come from
an imperfectly sharpened knife.

3. Un-scorched, un-fused edges – The buildup of heat in the knife blade comes from the friction of the
blade passing through the fabric. This, in extreme cases, leads to scorching of the fabric, and, more
frequently, to the fusing of the raw edges of thermoplastic fiber fabrics, such as those containing polyamide
 or polyester. Solution to this lies is a well sharpened blade, a blade with a wavy edge, the use of anti-fusion
paper during spreading, spraying the blade with air-coolant/lubricant, slowing down the speed of the blade
and reducing the height of the lay.

Methods of Cutting

In the majority of cutting rooms today, the cutting process makes use of hand shears, a mechanised knife
blade in one of the several possible types, or a die press which stamps out the garment shape. Some of the
methods currently in use are described below:

1. Hand Shears – Hand shears are normally used when cutting only single or double plies. The lower blade
of the shears passes under the plies, and some distortion of the fabric might occur which can be avoided
with practice. Both left handed and right handed shears are available for left or right handed people. The
major disadvantage of the method lies in the time it consumes and the consequent high labour cost per
garment, but it is appropriate for made to measure garments.

2. Straight Knife – A straight knife is used where the quantities for cutting do not justify purchase of a
computer-controlled cutter. The elements of a straight knife consist of a base plate, usually on rollers for
ease of movement, an upright or a standard carrying a straight, vertical blade with varying edge
characteristics and an electric motor above it, a handle for the cutter to direct the blade, and a sharpening
device. The base plate on its rollers slides under the glazed paper which is spread below the bottom ply of
fabric in a lay. Normally, available blade heights vary from 10 cm to 33 cm. Normally available strokes vary
from 2.5 cm to 4.5 cm. The greater the blade movement, the faster the blade cuts the fabric and the more
rapidly and easily the operator can push the machine.
The straight knife is a common means of cutting lays in conventional cutting rooms because it is versatile,
portable, cheaper than a band knife, more accurate on curves than a round knife and relatively reliable and
easy to maintain. Even if a band knife is used for the main cutting operation, a straight knife would be used
to separate the lay into sections for easier handling.

3. Round Knife - The elements of a round knife are a base plate, above which is mounted an electric motor,
a handle for the cutter to direct the blade, and a circular blade rotating so that the leading edge cuts
downwards into the fabric. Blade diameters vary from 6 cm to 20 cm. Round knives are not suitable for
cutting curved lines in high lays because the blade does not strike all the plies simultaneously at the same
point as a vertical point does. Therefore, a round knife is used only for straight lines or lower lays of
relatively few plies.

4. Band Knife – A band knife comprises a series of three or more pulleys, powered by an electric motor, with
a continuously rotating steel blade mounted on them. One edge of the blade is sharpened. The band knife
passes through a slot in the cutting table in a fixed position and the section of the lay to be cut is moved
past it.
Band knives are used when a higher standard of cutting accuracy is required than can be obtained with a
straight knife. Pieces to be cut are first cut on a block, and then cut exactly on a band knife.

5. Notchers – Many garments require that notches be cut into the edges of them to enable alignment during
sewing with other garment parts. Specialized notching equipment provides greater accuracy because a
guide lines up the notcher with the cut edge to give consistent depth of notch at a consistent right angle to
the edge.
6. Drills and thread markers – Where reference marks are needed away from the edge of a garment part,
such as for the position of the pockets, darts and similar features, a hole is often drilled through all the plies
of fabric in the lay. The drill mounting includes a motor, a base plate with a hole to allow the drill to pass
through, and a spirit level to ensure that the base is horizontal and hence the drill vertical. On many fabrics,
the drill is used cold and the hole remains visible until the sewing operator comes to use it. On looser
weave fabrics, where the hole may close up, a hot drill is used which will slightly scorch or fuse the edges
of the hole. A hypodermic drill may be used which leaves a small deposit of paint on each ply of fabric. If it
is important that no mark remains on the fabric, a long thread may be passed through the lay which is then
cut with scissors between each ply, leaving a few centimeters visible on each garment panel. All drill holes
must eventually be concealed by the construction of the garment.

7. Computer controlled cutting knives – This method provides the most accurate possible cutting, at high
speed, and to keep the larger systems fully occupied they are frequently used in a central cutting facility
that supplies a number of separate sewing factories. A typical computer cutting system has a table with a
cutting surface consisting of nylon bristles which support the fabric lays but are flexible enough to permit
penetration and movement of the knife blade which is supported only at the top. The bristles also allow the
passage of air through the table to create a vacuum, reducing the height of the lay and holding it in place.
The carriage supporting the cutting head has two synchronised servomotors, which drive it on tracks on the
edges of the table. The cutting head contains a knife, automatic sharpener and a further servo motor which
rotates the knife to position it at a tangent to the line of cut on curves. A sheet of airtight polyethylene
covers the top of the lay, which assists the creation of a vacuum and allows significant compression of the
lay. Control cabinet houses the computer and the electrical components required to drive the cutter, its
carriage and the vacuum motor.

The spreader spreads the lay on a conventional cutting table equipped with air floatation. Paper is spread
below the bottom ply so that the lay can be moved onto the cutting table without distortion and so that the
bottom plies are supported during the cutting operation. This paper is perforated to enable the vacuum on
the cutting table to operate to compress the lay. The cutting table does not need to be as long as the lay
and its bristle surface can consist of a conveyer which assists in the transfer of the lay, in sections, from the
spreading table and of the cut work onto the bundling tables.

8. Die Cutting – Die cutting involves pressing of a rigid blade through the layed fabric. The die (called a
clicker in the shoe industry) is a knife in the shape of the pattern periphery, including notches. Freestanding
dies generally fall into two categories. They can be of strip steel, manufactured by bending the strip to the
shape required and welding the joint. These cannot be sharpened and must be replaced when worn.
Alternatively, they can be heavier gauge, forged dies which can be re-sharpened but which are five times
the price of strip steel. They provide a high standard of accuracy of cutting but, because of the cost of the
dies, they are only appropriate to situations where large quantities of the same pattern will be cut. Die
cutting also offers much faster cutting than knife cutting for the same depth of cut. It is proportionally more
economic for small parts which have a greater periphery in relation to their area.

Cutting Room Terminology

• Baker’s trolley: A wheeled rack used to transport sections of the lay from the cutting table to the band knife
and from the band knife to the sorting operations.

• Band knife: An end less blade vertical knife, around which the work is moved over the large cutting table.
• Bias: ‘Cut on the bias’ – cut at an angle to both the warp and the weft of the cloth, at 45 degree.

• Blocking out: Cutting roughly around a part which is subsequently cut very precisely, by various means.
Also for splitting the lay, to assist handling to the band knife.

• Bowing: A fault in woven cloth in which the weft is not straight across the piece but has curve.

• Clicker press: Used for parts of intricate nature and repetitive, also for parts requiring a high degree of
accuracy.

• Cross: ‘Cut on the cross’ – Cut at right angles to the grain of the cloth (On bias).

• Damage: A fabric fault.

• Die cutting: Used where accuracy is important and there is enough repetition.

• End loss: The cloth at the end of the lay that is not covered by the marker.

• Face one way spreading: The face side of each ply faces the same way (up or down)

• Face to face spreading: Method of spreading in which the cloth is alternately facing up or down, as a result
of continuous to and fro movement of the roll over the lay.

• Face to face one way spreading: Used for directional fabric where the pile (direction) is required to lie in the
same direction on all the plies.

• Layout (pattern layout): The geometrical layout of the pattern pieces in a garment, which is cut around to
produce the parts of the garment.

• Marker: a) A man who prepares the pattern layout and/or who marks the layout onto the lay or onto a paper
or a cloth. b) A piece of paper, cloth etc. representing the layout.

• Notch: A small cut into the part, which aids the location during assembly by indicating to the operator some
requirement for matching with other notches or positions in the garment.

• On the fold: Method of finishing the cloth so that it is folded to half its width.

• Shading: Means colour in cloth. It is commonly used to imply that a particular bit/roll of cloth is different in
shade from another bit.

• Shade Numbering: Process of numbering parts to ensure they are of same shade.

• Slub: A local thick place in the yarn in a cloth usually caused by error but in some cloths it is introduced
purposely.