In the fashion industry there are many terms that we use, we wanted to explain a few of these to help customers make good decisions when purchasing their clothes.
GSM is simply the weight of the fabric, grams per square metre. It is measured by cutting a circle of fabric out with a special cutter and weighing it on fabric weighing scales. Knowing the GSM will let you know how heavy the fabric of your garment is going to be.
Just to explain a couple of things . . . . Raw fibre (cotton, linen, bamboo etc) is processed and spun into yarn. The yarn is then woven or knitted into fabric.
So back to the weight of the final fabric, this can vary due to a few things.
The thickness of the actual yarn
Some yarns are made thicker than others. For example wool fibre is different thicknesses which are referred to as microns. The smaller the micron, the finer the wool. So a yarn of finer micron wool would be lighter.
The composition of the yarn
Some fibres have more actual weight than others, therefore when spun into yarn, they start off heavier. Our bamboo jersey weighs so much more than organic cotton jersey. Bamboo simply is heavier.
The weave of the fabric or style of knitting
Some fabrics are a loose weave and very open or sheer. Others are tightly woven and therefore more yarn is used.
All of things vary when it comes to fabric, making the GSM something tangible that we can look at to decide to suitability of the fabric.
How to weigh a fabric
First you cut a circle of the fabric. This is done with a cutter (see below) and you are best to cut two at once from different parts of the fabric. Fabric can vary from one side to the other, so you cut two and do an average.
You then simply weigh it on the fabric weighing scales to get your GSM
When we get our new batches of fabrics in, we weigh them to see what the weight is. 5% up or down is the industry standard on variance.
To show how this info is relevant to you, our organic cotton Bestowed label is mostly 3 different types of cotton knits.
Most of our Bestowed dresses and tops (Blythe, Dita, Nasturtium etc) are in a 100% cotton knit which is like your t shirt fabric. This fabric weighs 140-150GSM. It's heavy enough to not be sheer when worn as a dress but still light enough to wear in summer.
Pics below are 140gsm fabric
Our superfine cotton knit which is the fabric we use to make our Quirk shrug, Ester cardi, Swivel top, Loopy scarves etc is very light and sheer and only weighs 60GSM. It's only 1/3 of the weight of the other fabric.
Pics below are 60gsm fabric
Our stretch organic cotton knit has 8% Lycra in the yarn to give it more stretch and return than the knit fabric without Lycra. This is used in styles like the Trinity pants, leggings and fitted singlet tops like Daria. We also use this fabric for many waistbands in both Bestowed and RANT. This fabric weighs 220GSM.
Pics below are 220gsm fabric
Our Australian made bamboo jersey has varied a lot over the years and we decided that we prefer it to be heavier as we can use it then for both tops and bottoms, as the lighter batches are only suitable for tops. The thicker the fabric, the longer it lasts and that's important to me. Also a thicker bamboo tops covers more, making the tops more flattering to wear. The bamboo jersey has varied from 230GSM - 300GSM. The new batches that we have had made, we request 280-300GSM.
We are going to include the GSM on the new products we put online starting this season. It's a little hard with some existing styles as we have run them for many seasons and the batches all vary, but we will do our best to add this extra information now you are all educated on fabric weights.
The Bestowed garments already have the GSM included in the fabric description on each product.
I hope this has been interesting and helps you when making a decision about purchases. If you ever need extra info or help deciding if one of our garments is suitable for what you're needing, call or email us.