Pattern grading

useful to apparel tech,fashion tech students.

1. Pattern grading R.S.BALAKUMAR Associate Professor,.DFDA /HITS. PADUR-CHENNAI-603103

2. Pattern grading  is the process of turning base size or sample size  patterns  into additional sizes using a size specification sheet or  grading  increments. This can be done manually or digitally using computerized  pattern  cutting software. These increments are referred to as garment grading rules. Each specific clothing market area and level has different grading rules.

3. Standard grading rules  are given as ergonomic measurements of the body. This can be done online or in  pattern grading books . When producing a clothing line, you will need a grading system to target a specific  target market . Grading  is a necessary step that must be taken before approaching sample manufacturers or factories, because they require card sets of your specific patterns and an order of garments to be produced. Grading determines how your garments will fit in all sizes. . Having a variety of sizes for each of your garments fills out your minimum garment order cost effectively. Grading will not create shape, but will only increase or decrease size of original shape.

4. Methods of Grading . There are three basic methods of pattern grading. These include: Cut and spread:  This is the easiest method, which acts as the basis of the other two methods. To perform this method, you must cut the pattern and spread the pieces by a certain amount to grade up, or overlap the pieces to grade down. The only tools you will need for this method are a pencil, tape, ruler, and scissors. Pattern shifting:  Pattern shifting involves increasing the overall dimensions of a pattern by moving it around at a constant distance. After you move it, you redraw the outline in order to produce the same results as cut-and-spread. Computer grading:  Computer grading is the most recent development in grading technology. It is also the fastest method. Computer grading, however, is expensive and usually only large manufacturers can afford it. Computer grading takes the processes of the two former methods and digitizes them. There is not a superior method; they are all equally capable of producing a correct garment grade.

5. Women's sewing patterns are generally designed to fit a specific size (usually an 8 or 10). That is the sample size, and the fit is perfected on that sample. Once the fit is approved for that size, the pattern is "graded" for a full range of sizes (usually size 4 to 18, for misses sizes).

6. The "grade rules" refer to the amount of change between sizes, for each measurement point.  For example, the bust, waist and hip "grade" 1" between sizes for most of the Misses size range.   If you started with a size 8 dress and needed to make another one in a size 10, you'd make the bust, waist and hip 1" larger.  You'd do this primarily by making the adjustment at the side seam, and  distribute the 1" size difference evenly at each seam.

7. Grading in the apparel manufacturing industry is well known as the art of proportionally increasing or decreasing a given size pattern part from one size to another, retaining everything true to its original form. The grading network for a block pattern is also the basic network for the components which have been developed from the block pattern. Article Contributed by-R.S.BALAKUMAR SOURCE-FIBRE 2 FASHION.COM

8. There are many techniques involved in the grading of garment pattern but they all have one common principle- the basic grade. Grading system can be classified in to the following two broad systems: 1. Track Shift System or Two dimensional grading. 2. Draft Grade System or Three dimensional grading.

9. Two-dimensional system: Two dimensional grading systems only grades a pattern for girth and height and its application is therefore limited to loose or semi drape garments because it retains the stock size suppression throughout the size range. This system is more apt to a very loose fitting garment such as a shirt or blouse with a limited range to say, 10-12-14, may be safely graded using a two dimensional system.

10. Three dimensional system: This system not only increases a pattern for size but it also increases or decreases suppression in the following areas: Bust to shoulder Hip to Waist Elbow to wrist

11. Three dimensional grading is the optimum system and should be used whenever possible, particularly when grading close fitting or skin-tight garments and garments that progress in size from 10 to 22. The most important garment area is the bust to shoulder suppression quantity. A good working knowledge of pattern cutting is required to use a three-dimensional grading system.

12. Types of Garment: There are two main categories, they are: Close or skin-tight fitting garments Loose or semi drape garments. The closer the garment fit, the more important it is to select a sophisticated garment grading system which adjusts the garment with the garment suppression. If the garment fit is loose the value of adjusting the garment suppression decreases and a two dimensional system becomes more advisable.

13. Number of sizes:  This may depend a little on whether a garment is close or loose-fitting, but it mainly refers to a situation where the company or firm only offers a limited number of sizes, the complexity of the grading system, etc.  

14. Types of Fabric: For grading purpose fabrics may be classified in to two broad types: Stretch Non-stretch Stretch fabrics are more for adjustable and will fit readily to the body contours or silhouettes and therefore, it can be employed. A non stretch fabric has the reverse effect and must be kept under the control and in balance through the size range.

15. Grading Techniques: The draft or multi size (Nested) grade. The track or single size grade.

16. The Draft Grade: This term applies when the pattern is returned to its original block form or when the increment is applied to the actual pattern draft. This results in the entire size range being super imposed one on top of another and can also be described by the term 'Nested' or 'Tracked'. The individual pieces of pattern for each size are then picked or traced off onto card. A draft grade can be either two or three dimensional. The three dimensional draft grade is considered to be the ultimate method for applying grade increments.

17. The Track Grade: This term is used when grade increments are applied to individual pieces of pattern by moving the base pattern pieces along with the predetermined tracks. Making the pattern section by section and thus altering its size. This system is usually two dimensional but can be adapted to a three dimensional system with difficulty.

18. Following are the steps for manual grading: 1. To prepare for grading 2. Grading the pattern 3. Check the pattern grading measurements 4. Completing the pattern.

19. The tools required for grading are as under: 1. Parallel rules 2. Awl 3. Carpenters pencil 4. Proportional divider 5. French curve 6. Arm hole curve 7. Tailors square 8. Notch maker 9. Grade ruler 10. Measuring tape 11. Colour sketch pen or pencils

20. Size intervals: A sizing system is a pre-determined size interval i.e. the major girth difference between each size. The variation in the size is in the order of plus or minus 2cm then the logical size interval would be 4cm. Practically, intervals smaller than 4cm result into more used sizes of the range.

21. Size charts: There are two types of size charts in normal use. 1. Body measurements: This type of chart provides the human body measurements for each size and these measurements are used as a basis for constructing a pattern with the requisite amounts of ease. 2. Garment measurements:-This chart gives the details of the finished measurements, specification for each size and is used for pattern grading purpose. A size is a combination of measurements and each combination is designated by a symbol which is a common code between the apparel manufacturer and the consumer.

22. The 'X   ' AXIS and 'Y'AXIS: The x -axis for body and y-axis for body and skirt grades would be a line on, or parallel to the center back or center front. This is always true, if straight y-axis is a line on, or parallel to a major girth line such as the bust, waist, or hip.

23. The different types of grading that are still in usage are: manual grading, machine grading, and computerized grading are still used. The practice of garment grading is mainly concerned with efficiently producing dimensionally accurate patterns. In order to do this, some basic rules must be always observed. There is no hard and fast rule as how to actually produce the sets of graded patterns and the choice of working method is also dependent on an individual's accuracy and convenience.

24. Image courtesy: Threadsmagazine.com R.S. Balakumar has M.A (Sociology), MLM. He is a member of the Council of the ISTE member, New Delhi and specializes in Garment Technology.

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