There are various types of elastics used in underwear and pyjamas as listed below:

Underwear/ Pyjama elastic is meant to come in direct contact with skin and accordingly should be soft. The elastic has a plush-back to provide extra comfort. It will not narrow when stretched and is shrink resistant. This elastic is a great option for items you will wash and wear.  

Buttonhole elastic comes with evenly spaced holes created with the intention of using a button. This can be a great option for children clothing or for maternity clothes

Drawcord Elastic is a specialised elastic that has a drawstring running through a channel in the middle of the elastic. It is perfect for sweat pants, sports wear, shorts, and many more uses that requires a quick tightening.

Jacquard elastic is a fashionable weaving technology with an exquisite  three-dimensional appearance and many beautiful patterns. It is made by using high and fine quality raw material and the design is customised as per the need of the customers.