Theatre curtains are large curtains that are designed for a variety of different purposes. Many of them are made from black materials because they are designed to block extraneous light coming on to the stage and spoiling the performance. These are usually made from heavy materials such as heavyweight velour or perhaps from black wool serge. Not only can these curtains block light, but they can also help to reduce noise. However, these blackout curtains, as they are also known, may sometimes be made of lighter materials but lined at the back in order to block light.

Many theatre curtains have a pocket across the bottom of the curtain which can hold a chain or heavy metal pipe in order to stretch them tightly and prevent them from moving about.

In many theatres the curtains are referred to as "flown". They are suspended from battens high above the stage and out of sight of the audience and can be wound up and down as required, and they are called fly curtains because they "fly" into what is called the fly loft above the stage. With a fly system the curtains are not referred to as "up" or "down" because those terms are used to describe the parts of the stage, upstage being towards the rear, while downstage is at the front nearest the audience. When they are up the curtains are "out" and when down they are "in", as in "out of view" or "in view". Complicated, this theatre curtain business, isn’t it?

It can get even more complicated. There are several different curtains which are used for different purposes. The curtain which is the one that the audience notices first is the front of house curtain, also known as house curtain, house drape, main curtain, main drape, and tabs. This hangs at the front of the stage, or downstage, and is just behind the proscenium arch. It is used to divide the audience from the stage and hide the set before the play begins. It is also used at intervals or in between scenes so that the stagehands can change the set.

There is also a safety curtain which is in front of the front of house curtain and may be made of solid steel sheet, or fireproofed heavy material and is deigned to be lowered in case of a fire breaking out on stage or in the wings or backstage. This protects the audience should this happen, and they are often designed to drop automatically if a holding line is cut.

Teasers and tormentors are used very often to create a reduced size of proscenium and consist of one teaser and two tormentors, one each side of the stage. These are located just upstage, or behind, the front of house curtain. The teaser, which goes in and out, is flown from a dedicated batten so that the actual height can be adjusted independently. There are also what are known as "hard" teasers and tormentors which are made of thin plywood and are covered in very dark or black light inhibiting materials.

Then there are legs and borders. Legs are narrow drapes that are used to hide the wings on each side of the stage. Borders are wide curtains spanning the width of the stage and are used to hide lights and scenery that are in the fly area, or fly loft. Drapes are another curtain hanging at the side of the stage and are known in the UK as "up and downers" because they run from upstage to downstage to help hide the wings. In other countries they are known as tabs. We said this was confusing!

Then there is the backdrop which hangs at the back of the stage and usually has some sort of scenery painted on it that fits with the scene being played by the actors.

A cyclorama is a large curtain that is hung upstage which can be lit up to represent to represent the sky, for instance, or other backgrounds – perhaps mountains in the distance.

A scrim is another curtain which is made of an open-weave type of fabric and can appear opaque when lit from the front but can become transparent when something or someone is behind it and is lit up.