All you need to clean anything should be within a topic below:
Care labels are often left off of curtains when they're made and a good tip is to look on the selvedge (the very edge of the fabric where the weave doesn't show) as they are often printed there. Clearly this edge will only be visible from inside the lining or on the reverse of the curtain at a seam. Look at a few of the seams as they may not be printed regularly.
The main concerns when cleaning curtains are shrinkage and loss of colour on any surface print. As a general rule if you have curtains that match any other part of the room (suites, duvet covers etc.) then you should aim to clean all elements of the set the same way. Changing from one method to another is a recipe for disaster, as you're almost certain to end up with different colours to different pieces. What's more, don't believe that just because your duvet cover is washable your curtains are too. Curtains have buckram, facings and linings that duvets don't and any of these elements may change the items cleaning properties.
The first consideration is always fabric so we'll look at these first before detailing the individual requirements of specific curtain types
Velvet curtains are normally made of cotton or silk but they may be viscose or another man made fibre. The problems with cleaning velvet are crushing the pile and shrinkage, both of which can be difficult to avoid when washing. It is probably best if you dry clean velvet curtains even if the instructions suggest they are washable unless they specifically exclude dry cleaning.
One rule to stand by with any surface printed pattern (one that shows only on one side of the fabric) is that if you have anything else in the same fabric you must be able to wash that too. Often there is a glaze on top of the print which will be dislodged in washing or whose look will be altered in some way. This can lead to a disaster if you find you can only do some of the fabric in a particular way (and you've already done it).
You're most likely to decide to wash plain cottons but be sure to follow the washing instructions. Another point to be aware of is that shrinkage can still occur even if the curtains are washable and this is unlikely to be taken as a fault with the fabric. Take the lowest heat setting together with a gentle action and try to dry the curtains naturally (i.e. don't tumble if you can help it).
Silk is a delicate fabric and the weight of a pair of curtains when wet can make machine washing a dangerous business. What's more when washed the creasing is likely to be very bad and you may not have the equipment to recover the overall soft look they had before washing. We suggest dry cleaning but please check the curtain for sun bleaching especially on the edges and folds as this form of damage can cause rips in the fabric during the cleaning process.