GSM/GLM
The weight of a fabric can be measured in two ways, either as the ‘weight per unit area’ (GSM) or the ‘weight per unit length’ (GLM). GSM refers to the weight of the fabric in grams per square meter, whereas GLM is the weight in grams per linear/running meter. Since the width can be different for different fabrics, GLM depends on the width of the fabric. Both these units of measurement can help decide which fabric is lighter or heavier.
You can find out the GSM of a fabric if you know its construction
For E.g. If you have a 58” width 60/1 x 60/1 fabric with the construction as “177 x 87”
You can use the following formula to get the approximate GSM (not taking into account the “Crimp %”)
GSM = {(EPI/Warp count) + (PPI/ Weft count)} × 25.64
GSM = {(177/60) + (87/60)} x 25.64
GSM = 112.82
Once you know the GSM, you can also get the GLM easily as long as you now the width of the fabric
GLM = (GSM × Fabric width in inches) / 39.37
GLM = (112.82 x 58) / 39.37
GLM = 166
