Topic
Fabric and garment test guides: GSM, tensile, bursting and seam strength, pilling, dimensional stability, color fastness and construction analysis.
Physical tests measure how a fabric or garment behaves rather than what it contains: how heavy it is, how strong, how stable after washing, how it holds its color and how it wears. These notes explain the principle of each test and how to read the result, and they point to the official standards for the exact procedure. Fabric testing standards and methods and the ISO, ASTM and AATCC test methods map give the overview. The rest are one note per test: GSM, tensile strength, bursting strength, seam strength, pilling, dimensional stability, color fastness and fabric construction analysis.
17 notes
Bowing and skewing happen when weft yarns or knitted courses are not straight and square across the width. How to measure bow and skew, where they come from in finishing, and why they cause twisted garments and mismatched checks.
Bursting strength measures the pressure or force needed to burst a fabric stretched in all directions. Why it is used for knits instead of tensile tests, the hydraulic, pneumatic and ball burst methods, and what affects results.
Color fastness to perspiration checks whether a fabric's color changes or transfers when soaked in artificial sweat. The test principle, acid and alkaline solutions, grading, and how to improve results on dark shades and sportswear.
How color fastness to washing is tested with a multifiber strip, how change in shade and staining are graded with grey scales, the main ISO and AATCC methods, and what to do when a fabric fails.
Colorfastness describes how well a dyed or printed textile keeps its color and avoids staining other materials. Learn the main test types, how grey scale ratings work, how to read a report and what to do when a fabric fails.
Rubbing fastness, also called crocking, measures how much color transfers from a fabric to another surface by friction. How the dry and wet tests work, what affects the result and how dyehouses and printers improve it.
How to analyse a woven fabric sample: count ends and picks per inch, identify the weave, find warp and weft counts from yarn removed from the fabric, measure crimp and GSM, and write the construction in standard form.
GSM is the weight of one square meter of fabric in grams. Learn how to measure it with a round cutter, calculate it from any sample size, estimate it from construction, and control it in production.
How a fabric shrinkage (dimensional stability) test is done: specimen size and benchmarks, conditioning, wash and dry procedures, the shrinkage formula with worked examples, in-house checks versus lab tests, and how to read and act on the report.
Why woven and knitted fabrics shrink, how shrinkage is measured and calculated, typical causes in knitting, weaving and finishing, and how factories control shrinkage through relaxation, compaction and pattern allowance.
An overview of fabric testing for apparel: what each group of tests measures, how the main methods work (including Martindale abrasion, air permeability and UPF), which ISO, ASTM and AATCC standards are used, how to build a test program by product, and how to read a test report.
A reference map of the test methods most often named in garment and fabric test programs: what each family covers, how ISO and AATCC or ASTM methods relate, and why results from different methods cannot be compared directly.
Pilling tests rub or tumble fabric to simulate wear and grade the pills formed. The main methods (pilling box, Martindale, random tumble), how grades 1 to 5 work, why fabrics pill and practical ways to improve pilling resistance.
Seam strength tests measure the force needed to break a seam; seam slippage tests measure how far yarns pull away from a seam under load. Methods, how seams fail, and how thread, stitch density and seam design affect results.
Spirality makes wales slant and side seams twist around T-shirts after washing. Why single knits twist, how spirality is measured, the main causes in yarn, knitting and finishing, and how to reduce it.
Stretch is how far a fabric extends under load; recovery is how well it returns. What drives stretch and recovery in knits and wovens, elastane content, how the properties are tested, and what goes wrong in garments.
Tensile tests pull woven fabric until it breaks to measure maximum force and elongation. The difference between strip and grab methods, the main ISO and ASTM standards, how to read a result, and what lowers fabric strength.