Size Specs - Size Specification

The term "size spec" is short for "size specifications".  The size spec document is occasionally referenced to as a spec sheet or spec sheets.,  This document or file is basically a guide for clothing factories to follow for garment measurements and sewing techniques.  The file contains garment manufacturing specifications that help the factory produce the garment as per the buyers requirement.  The specifications are intended as a list of instructions for a garment factory to following in order to maintain consistency during the bulk production of clothing and fashion accessories. 

The size spec files may also contain information regarding the garments trim requirements.  The spec sheet will indicate the button sizes, twill tape lengths, zippers, waistband widths, draw cord length etc.  Size specs, may also contain a design sketch to help the factory view a complete rendering of the intended garment.  The file may also include brand label and care label requirements for the product.

Size specs are typically provided to factories as an instructional tool to follow when manufacturing clothing or fashion accessories.  The size spec document includes points of measure as well as detailed sewing instructions.  For example, the spec file may include a hem measurement as well as indicate the stitching to utilize on the hem.  For example, 1" hem, 1/14" cover stitch.  This instructs the factory how to create the hem of the pant.

The spec sheets help assure a consistent garment fit.  A well developed spec package may include a how to measure guide.  If it is not included on the spec file, the factory should at least be provided with a separate manual providing them with clear indication of how you wish for them to manage the point of measure.  The "how to measure" guide is intended to ensure that all manufacturers are using the same methods of measurement.  Here are a few examples of a point of measurement method:

Bust / Chest - Lay the garment flat and measure the garment straight across one inch below the armhole.  (note: it is important to indicate location below the armhole or from another point so that the person taking the measurement has a specific starting point).

Waist - Relax or extended measure from side to side along the center of the waistband or waist seam.  For extended measurements - measure as above with elastic or knit fully extended.

Inseam - lay one entire leg flat measure from the top of the garment to the bottom of the leg following the side seam.

All measurements should be taken with a plastic or fabric tape measure.  Generally all measurements are to be taken with the garment laid on a flat surface with all wrinkles gently smoothed out.  Measurements should be taken with zippers or buttons fully closed unless otherwise stated.

Below are a few examples of the the wording you may see on a size spec file.

When indicating a measurement, most companies also provide what is refered to as an available tolerance.  For example, if you are supposed to have a 34 inch waist, the buyer may give you a 1/4 inch tolerance.  If you have a quater inch tolerance for a 34 inch waist, this means that if the garment waist measures 34 1/4 inches or 33 3/4 inches, you will be approved.  Because you are within the tolerance that they allow, you will be fine.  Therefore, when reading the size spec file, you should read the measurements but also be certain to check the tolerance permitted.  Each buyer may provide a different tolerance.

Size spec files are important to clothing factories, fashion merchandisers, pattern makers, etc.  You will find that many PDM packages and pattern making software provides methods to manage size spec files in a fashion software environment.  If you are a small start up company, you can create your spec packages on programs such as excel or any other similar software.