Because so many haberdashery shops these days carry only one basic weight of interfacing,you may think that there is little choice,when the choice is really enormous!

First decide if you need it to be fusible(iron-on) or sew-in.Many professionals will only use sew-in,because many delicate fabrics won't take the iron.and also because there is a certain amount of flexibility. On sturdier fabrics,fusible is often easier,but you obviously need to make sure the surface cloth is perfectly smooth and flat before ironing on the interfacing. If you have set iron temperature carefully,the interfacing will not easily remove if you have made a mistake!

Next think about the weight.Ideally,the interfacing should be the same weight or a little less than that of the fabric.If the fabric is very drapey,you can buy soft interfacings,and even ones with strengthening threads in one direction. It is even possible to buy fusible cotton or satin interfacings,the first often used by shirtmakers and the second by gown makers.

It has recently become possible to buy really heavy interfacings,ideal for the bagmaker,as the cardboard pieces often resorted to are not a good idea!

Remember that most interfacings are also available in a very dark grey colour,which will not "glint" through a light coloured loosely-woven fabric.

A final good tip,if you can't afford to carry a range,is that a lightweight fusible can always be ironed onto itself to make a heavier weight!

And when buying,don't confuse the shopkeeper! An INTERLINING is a different thing altogether!