How Do I Turn a Layer into a Layer Mask?

You can turn a layer into a layer mask by adding a mask to a layer and then using that mask to hide or reveal portions of that layer as explained in the YouTube video titled "How to Create a Layer Mask in Photoshop".

Understanding Layer Masks

A layer mask is a non-destructive way to control the visibility of a layer. Unlike directly erasing parts of a layer, a layer mask allows you to hide or reveal different areas of a layer without permanently altering its pixels. This gives you greater flexibility and the ability to make changes later.

How to Convert a Layer into a Mask

While the question implies turning a layer directly into a mask, that is not typically how the process works in software like Photoshop. Instead, you add a mask to a layer, then use it to control the layer's visibility. Here's a simplified way to think about it:

1. Select Your Layer: In your layers panel, click on the layer you want to apply the mask to.
2. Add a Layer Mask: There is usually a button or option to add a layer mask (e.g., in Photoshop, a button that looks like a rectangle with a circle in it). This will add a white mask next to your selected layer.
3. Modify the Mask: Now, you can 'paint' on the mask itself using black, white, or shades of gray:
   • Black: Hides the corresponding portion of the layer.
   • White: Reveals the corresponding portion of the layer.
   • Grayscales: Shows varying degrees of transparency in the corresponding portions.

Example Scenario and Practical Insights:

Let's say you have a photo of a person on one layer and a background image on another layer below it.

• Goal: To isolate the person and put them on a new background.
• Process:
  1. Select the layer with the person.
  2. Add a layer mask. The mask will be white by default which means the entire layer is visible.
  3. Use a black brush to paint over the background surrounding the person on the mask itself.
  4. As you paint black on the mask, the areas you are masking out will hide the person's layer, revealing the background layer beneath them.
  5. If you make a mistake, you can paint with white on the mask to restore the layer.

Conclusion

While you cannot turn a layer directly "into" a layer mask, you can apply a layer mask to a layer and manipulate that mask to hide or reveal parts of the layer. The layer itself remains unchanged and is still available if the mask is modified or removed. This approach offers a more flexible way to work, and is a fundamental part of image editing.