Pattern Grading Methods in Apparel

Pattern grading: 

Pattern grading is the process of manual or digital adjustment of your sample pattern from one size to another with the help of size specification chart and without changing the original style, initial look, and shape etc. 

Pattern grading means the step wise increase or decrease of a master pattern piece to create larger or smaller sizes. The starting point can be smallest size or the middle size. Pattern grading alters the overall size of a design but not its general shape and appearance. Computer aided pattern grading system utilize internal calculation algorithms (grading rules) for pattern construction.

 

Fig: Garment pattern grading

The way of resizing the master pattern is called "grading." In the apparel industry production patterns is generally made for medium size but if the buyer requires different size, then manufacturers have to grade the dimension like S, L, XL, XXL, etc. For example, if the sample pattern size is 10(M), then it must be made larger to accommodate sizes like 12(L), 14(XL) and 16(XXL) and to make smaller for sizes 8(S) and 6(YS). 

The objectives of pattern grading is to properly increase or decrease the size of a master pattern, but keep up with shape, fit, balance, style and scale of the apparel. Pattern grading commonly used in apparel industry and fashion design sector.

Types of garment pattern grading techniques: 
In the apparel manufacturing basic pattern grading methods are mainly divided into 2 types. They are

1. Manual pattern grading or two dimensional grading.
2. Computer-aided pattern grading or three dimensional grading.

1. Manual pattern grading: 
The desired range of sizes is created, one by one, using a pattern template. Marks are made around the master pattern at the appropriate distances and the marks the later joined up to form the enlarge pattern.

Fig: Manual pattern grading

In this way a full set of templates, the “pattern set” is generated. 

Grading machine: 
A grading machine eases the task of creating the pattern set. The device grips the master or basic pattern and displaces it by a precise vertical and horizontal distance, after which the appropriate edge can be traced. 

Now-a-days manual pattern grading methods are classified in 2 ways. These are mentioned and shortly describe in below: 

   a. Cut and Spread 
   b. Pattern Shifting

a. Cut and Spread: 
Cut and Spread grading method are starts by the use of tracing and marking techniques from the original master pattern to a white paper. Ensure that all the marking lines like grain line, darts are visible here. In this method original patterns are cut vertically into 3 parts and spread the cutting pieces by a specific amount to grade up. Then overlap them to grade down. To do this process, only scissors, a pencil, measurement tape, and a ruler is required. 

b. Pattern Shifting: 
Pattern shifting is another process of pattern grading. When pattern or fashion designer want to increase or decrease the overall dimensions of a pattern to get different sizes is called pattern shifting. To make the pattern larger, transfer the original pattern onto another sheet of paper. To make it smaller, they will have to trim the edges to the desired dimensions. It is done by moving the master pattern a certain measured distance up and down and left and right using a special designed ruler. To get the same result as the cut and spread method designer redraw the outlines. 

2. Computer-aided pattern grading:

Computed grading (CAD) is the fastest pattern grading techniques. But when it first came, it was only used by larger fashion or apparel manufacturers for their production process. Now CAD is more affordable software. By this method every manufacturer’s get more accurate, precise, detailed patterns in a short time.

Fig: Computed pattern grading

Computer based grading systems operate in one of two ways:

1. The grading increments are feed into the computer and the different sizes are generated automatically using the same methods as applied for manual grading.
2. The pattern for each individual size is calculated separately starting from the data in the size specification charts.

The resulting nest of patterns can be displayed to scale on the computer monitor for visual assessment and if necessary, adjustment. 

Once the pattern set has been generated on the computer, it may be used in various ways, depending on the level of automation in the factory. 

In a fully automated system, the garment parts will be sorted automatically and arranged into a lay plan which can then be transmitted in the form of a control program to the automatic laying and cutting system. Alternatively, the patterns can be sent to a large plotting device where they will be drawn at full scale to serve as paper patterns for manual cutting. The patterns can also be used in an automatic device for cutting templates from more durable material.

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Garments Pattern Making Methods.

Pattern Making
Pattern making is a highly skilled technique which calls for technical ability, and a sensitivity to interpret a design with a practical understanding of garment construction. For successful dress designing pattern making forms the fundamental step. This function connects design to production by producing paper templates for all components such as cloth, hemming, fusible etc. which have to be cut for completing a specific garment. 

Pattern making is an art. It is the art of manipulating and shaping a flat piece of fabric to conform to one or more curves of the human figure. Pattern making is a bridge function between design and production. A sketch can be turned into a garment via a pattern which interprets the design in the form of the garment components. A pattern is flat while the body is not. The body has height, width and depth. Within this roughly cylindrical framework there are a series of secondary curves and bulges, which are of concern to the pattern maker. Darts are the basis of all pattern making. They convert the flat piece of cloth into a three dimensional form, which fits the bulges of the body. 

A pattern maker typically makes a pattern from a flat sketch with measurements or a two dimensionalfashion illustration. The basic pattern is the very foundation upon which pattern making, fit and design are based. The basic pattern is the starting point for flat pattern designing. It is a simple pattern that fits the body with just enough ease for movement and comfort. 

Methods of Pattern Making 
Pattern making involves three methods- 

1. Drafting
2. Draping
3. Flat paper pattern making

01. Drafting: It involves measurements derived from sizing systems or accurate measurements taken on a person, dress or body form. Measurements for chest, waist, hip and so on, and ease allowances are marked on paper and construction lines are drawn to complete the pattern. Drafting is used to create basic, foundation or design patterns. 

MEASUREMENTS 

Bust – measure just under the arms around the fullest part of chest. 

Waist – measure around narrowest part of torso. 

High Hip – measure 6 inches [15.5 cm] below waist around the hips. 

Back-waist length – measure from nape of neck to waist level 

Shoulder length – measure shoulder from ball socket to side of neck. 

Armhole depth – measure from nape of neck to under arm level. 

Back width – measure from armhole to armhole across shoulder blades. 

Neck – measure around base of neck. 

Tools use for Drafting 

A: Tape Measure 
This is likely something you already have in your stash, because if you have been making clothing you should have been measuring your body along the way! If not, pick up a good quality fiberglass tape measure today so you can start your pattern making off right with correct body measurements. 

B: Seam Ripper 
Like the tape measure, you probably have a seam ripper. You will use this in patternmaking for taking out your basting stitches when you move from the muslin fitting to the pattern drafting stage. 

C: Fine Point Sharpie Marker 
Muslin versions are always ugly because they are marked up, but you want to make your markings with a permanent and fine point. I like these push-button fine point sharpie pens as the cap always seems to get lost in my studio! These are quick and easy to use. 

D: Tracing Wheel 
To take your markings from the muslin stage to the patternmaking stage, this tool will pierce through the paper and leave behind marks to draft with a mechanical pencil. 

E: Rotary Cutter 
I like using my rotary cutter for the big broad strokes of cutting muslin. Make sure to use a cutting mat beneath your item to protect the cutting surface of the table underneath! 

F: Fabric Scissors 
Sharp, high-quality scissors are used for all your fabric cutting in sewing and patternmaking. These will shape the muslin down to the proper size after you have cut it big and broad with the rotary cutter. 

G: Tracing Paper 
I personally do not use this, but many designers like it for leaving marks behind on their muslins. I like a sharpie or tracing wheel, but try these sheets out and perhaps you will love them! Many people do. 

H: Scotch Tape 
It is inevitable that you will need to tape pattern pieces together and I find that basic Scotch tape is the best for this. 

I: Clear Rulers 
Having a variety of clear rulers in different shapes and sizes is essential in your kit for patternmaking. I like having a little one for marking in tiny areas, long ones for making marks for pin tucks, side seam lines, and other parts of the patternmaking process that call for something longer than average. I also have a quilting square with diagonal lines for helping square up corners and creating angles. 

J: Right Angle 
This is also a huge help in creating perfect 90 degree angles on your pattern. These are also available in clear plastic, which most people prefer. I have had this black one since art school and still use it. 

K: Curved Rulers
To shape arm holes, hip curves, hems and other lines that are not straight in patternmaking, it is essential that you have a few different curved rulers to get the proper slope in your pattern. 

Tools use for Drafting

02. Draping: It involves the draping of a two dimensional piece of fabric around a form, conforming to its shape, creating a three-dimensional fabric pattern. Ease allowances for movement are added to make the garment comfortable to wear. Advantage of draping is that the designer can see the overall design effect of the finished garment on the body form before the garment piece is cut and sewn. However, it is more expensive and time consuming than flat pattern making. Draping can be made on a Human body or on a stand. 

Fig: Draping

03. Flat Pattern Making: It involves the development of a fitted basic pattern with comfort ease to fit a person or body form. A sloper is the starting point for flat pattern designing. It is a simple pattern that fits the body with just enough ease for movement and comfort. Five basic pattern pieces are used for women’s clothing. They include a snug-fitting bodice front and bodice back with darts and a basic neckline, a sleeve and a fitted skirt front and back with darts. However, as fashion changes frequently women’s styles fluctuate frequently. These basic slopers are then manipulated to create fashions. Nowadays draping is also tested by Computer aid techniques. A basic sloper has no seam allowances, which facilitates its manipulations to various styles. It has no design interest, only construction lines are marked on it. It is necessary that the basic structure of a sloper should be such that adjustments can be introduced easily. For a good pattern making, accurate measurements are of utmost importance. 

Pattern making by CAD system

The flat pattern making method is widely used in the ready-to-wear market because it is fast and accurate (Aldrich). 

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