A front curtain, also known as a (front-of-)house curtain, act curtain, grand drape, main curtain or drape, proscenium curtain, or main rag is the stage curtain or curtains at the very front of a theatrical stage, separating it from the house.

The front curtain is usually opened at the beginning of a performance to reveal the stage set and closed for intermissions as well as the end of a performance. The most common material for the front curtain is a heavy velour material, often with pleated fullness sewn into the fabric to create a more opulent appearance.

There are several styles of house curtains, which vary in construction, operation, and cost. Depending on a curtain's type, its fabric may be flat or pleated, and it may drape, hang, or do both. Some types open with the full curtain rising out, either via a fly system or by gathering upwards with lines; other types part in the centre and either travel horizontally on a track or are pulled out diagonally using lines (See below). Some styles require a mechanical advantage like a winch to operate, while others are done by pulling an operating line or handling the drapes directly.

The Austrian curtain or drape, also called a puff curtain, has multiple vertical lines (typically nylon) spaced evenly across the width of the fabric, which typically is a thin satin, charmeuse, or chiffon material that bunches well. Each line runs through a pulley at the top of the curtain and then horizontally to a common head block. The lines descend from the head block to a mechanical winch, which is used to raise the curtain. A winch is necessary to perform this function as the curtain would otherwise be too heavy for one person to raise.

As the winch turns, the curtain rises and is collected in a series of swags, which are accentuated by horizontal pleats (called festoons) sewn into the curtain from top to bottom, thereby giving it both vertical and horizontal fullness. Austrian curtains reached their height of popularity in the mid twentieth century. They are considered visually attractive and simple to operate and require little fly space, but have complicated rigging and are relatively expensive.

The Venetian curtain, also known as a profile or contour curtain, also has multiple vertical lines distributed across the length of the single panel of fabric (which is usually made with as much as 200% fullness and must be thin and soft so it gathers well). The curtain is opened by pulling on the lines. Unlike the Austrian, each line is independently operated, making it possible to control the shape and height of curtain openings. This type of curtain is typically the most difficult type to operate because of the many independent lines.

A variation on the Venetian and Austrian is the waterfall curtain. Instead of horizontal festoons, the curtain has vertically running pleats like a traditional theater curtain, but it still gathers from the bottom in a number of swags. The waterfall has a pipe batten along the bottom edge to ensure the lines rise evenly. It is somewhat similar to a Roman shade, but with only one batten and vertical pleats.

A brail curtain or drape in its lowered position appears as a pleated panel much like a traveler curtain; it is rigged, however, as an Austrian curtain: The multiple lines leading through rings sewn to along the seams on the back side of the curtain cause the fabric to gather along the bottom in swags as the curtain is raised. It has a faster action than a traveler curtain, and like an Austrian it requires little fly space.