Filler is added fibre to increase the weight or the size such as:
* an extra weft thread to create a ridge.
* a warp or a weft that is later removed to open up the weave.
* an added substance to increase weight and size–such as a glue-type of solution used to fill cracks or holes and add body; this is sometimes used in inexpensive cottons, so that when the fabric is purchased it feels good but washes straight out leaving a limp cloth. Starching can replace any missing filler.
* some cloths are designed to have filler–the South African fabric ‘3 cats’ is very stiff when it arrives, but washes to a lovely soft, manageable cloth that still has good body and drape.
Any filled cloths ( left unwashed) can be laminated to Holland cloth to make a very strong roller blind.