Our next step is making the mask. What is a mask? A mask is a greyscale image that is applied to a layer and is used to "mask "layers, that is, to hide and show parts of a layer, fade between layers, and/or create other special effects. A mask can be created from a selection, from an alpha channel, or an existing image. Masks can completely cover a layer, or cover a layer with varying levels of opacity. In our exercise, we are going to create a mask layer from the luminance of the gradient image we just made.

Go up and Left Click Layers, scroll down and Left Click "New Mask Layer", and scroll over and down to Left Click "From Image".

A Macro may appear as shown on the left. If so, Left Click "OK".

The next screen will appear. We will choose "Source luminance" and Left Click "OK".

Doesn't look like much, but there's our mask we need.

Some masks can be quite difficult to see or perform last minute tweaking. For that, users will come down the "Layers" Menu and click "View Overlay".

This is what it looks like if you haven't seen this step before. It's a little easier to see the mask now. There is no need for editing our work, so let's continue on.

Now comes the task of commiting the mask to the alpha channel and saving our work to disk (Hard Drive).

In the Layers Menu, scroll down tand Left click "Load/Save Mask" and scroll over and Left Click "Save Mask To Alpha Channel".

The next screen will appear and Left Click "Load".

Your Mask should now show the selection window about our Masked Gradient. A few more steps to go!

Now for a very important step: saving our work! Go to the Selections Menu, scroll down and Left Click "Load/Save Selection", scroll over and Left Click "Save Selection to Disk".

Now the name you type IS important, as this filename and storing it can be a great source for future mask building for your textures. Type in a name and Left Click "Save". Now that it's saved, delete the mask texture.

Now open/select the texture you want to apply the mask to.

With the floor texture highlighted, Open the Selections menu, Scroll down and Left Click "Load/Save Selection" and Scroll over and Left Click "Load Selection From Disk".