The virtual Look Master display can be added to or removed from the display by selecting Display|Look Masters from the Menu Bar or pressing [S5] from the main Softkey menu and selecting Look Masters from the large pop-up display.
NOTE:
When dealing with just intensities, you may want to think of Look Masters as conventional submasters. The term Look Master more accurately describes how these controls adjust intensity attributes while still recording and playing back other attributes such as Pan and Tilt (i.e, when addressing a Look via the command line, the Level wheel will adjust the fixtures' intensities while not affecting other attributes. Likewise, when playing a Look back using the Look Masters, different attribute families can be mapped to the handle in different ways.)
The colored triangle on the virtual Look Masters is there to indicate the Look Master type.
Green up arrows indicate an additive Look Master.
Red down arrows indicate an inhibitive Look Master.
A virtual Look Master Handle appears when you place the Mouse pointer on a Look Master and left click (and hold).
To change channel levels, hold the left mouse button down while moving the mouse up and down, raising and lowering the handle.
Release the left mouse button to release the handle. It will stay where you left it.
The order in which you select fixtures is preserved when you Record a Look. This order is restored when you use the Look to recall a group of fixtures and matters when you are using Fanning and effects.
You can get a Look's Properties by either right-clicking on the Virtual Look Display (see Display Menu) or using the [VIEW] or the [V] button on the QWERTY keyboard then selecting [S12]Look Master.

Select the Look Page then type in the Look Number to get the Look's Properties box:

The Label can be any text field you want. This text will appear in the bubbles in the Look Display, in the Virtual Look Master Handle, cues that reference this Look and in any dialog box that identifies the Look.
When you record a Look, you can choose whether or not it will be additive (pile-on) or inhibitive (reducing the level). Levels that are affected by an inhibitive Look Master appear like this:

Note:
Assuming you are dealing with Looks with similar Priorities, unless you choose HTP Intensity, the last look activated will take all levels to their new recorded level, even if that means lowering their level. Inhibitive Looks can hold cue levels lower than their recorded level.
Intensities can either be LTP or HTP. By default, when you record a Look, the Look Master will control the intensities in an LTP fashion, allowing you to Busk looks, taking levels up or down, with the last one winning. You can also make Looks resolve in a Highest Takes Precedence fashion by checking this box. An HTP Look will not lose its intensity to other LTP Looks unless the LTP Looks have a higher priority.
You change the priority of this Look to any value between 1 and 100 (highest priority is Priority 1). Higher Priority Looks (lower numbers) win. The exception is if another Look Master or Cue List with the same priority sets the attribute to a different level (again resolved HTP or LTP as determined by the properties of that other control). The default priority is 9 such that Looks win over Cue Lists which have a default priority of 10.
Each Attribute Family can have a different behaviour when this Look is activated. By default, Intensity attributes are set to Manual control, meaning that the level will be scaled by the handle's position from 0% to 100%. Other options are Snap Off Zero and Snap At Full. That means that the attribute will go to its recorded level without fading as soon as the handle moves off the bottom or hits the top.
Note: These behaviours are set automatically at record time. If both Intensities and other attributes are recorded into the Look, the Intensity Behaviour will be Manual and all the others will be set to Snap Off Zero. If you are recording attributes besides intensity (and specifically NOT Intensity attributes), the behaviours will be set to Manual.
See Also:
Using Looks in Command Line Syntax
Look Master Types (Additive and Inhibitive)