Silk has wonderful properties of movement, flow and luxurious sheen which come from its smooth, continuous, triangular fibres which reflect light. It is also a very strong, elastic fibre which can stretch 20-25% without breaking and will stretch back; that is, it has a memory. Once woven, it can have a wide variety of appearances and feel from delicate, translucent chiffon gauze to robust, opaque, slubby fabrics such as douppion. If you want to check whether a fabric is, in fact, silk you can burn a small piece. It should not burn easily and leaves a shiny black residue which crumbles to ash if you rub it between your fingers.
The weight of the yarn and the type of weave will naturally affect how silk dye flows and the techniques which can be used successfully. It is, therefore, important for a silk painter to be familiar with these so that an informed choice can be made of a suitable silk for a particular project.
There are three main types of weave, plain, twill and satin.
The numbers seen after a description of a silk eg habotai 8 refer to the weight of the silk. It is only necessary to know that the higher the number the heavier the silk. So a pongée 5 is a light, fine silk and a twill 14 is a lovely rich weight.