Masks Are Easy pg 4: Production Graphics with Wendy Peck at webreference.com

Masks Are Easy 4: PhotoShop Mask Basics

PhotoShop has a masking feature called Quick Mask that is different from layer masks. See the next page for more information on Quick Mask.

Create a layer mask
You cannot add a mask to the background layer. I will usually duplicate the background layer and then fill my background layer with a background color, often white. The illustration at the left shows a simple setup for preparing to add a layer.

There are two methods to add a layer mask. You can choose Layer > Add Layer Mask > Hide All or Reveal All. Hide all fills the layer mask with Black, masking the entire layer. Reveal All fills the layer mask with white, or applying no mask to the layer.

You can also choose the Add Layer Mask Icon from the bottom of the Layers window (highlighted with yellow). If you have no active selection, this choice will produce a mask with white fill, or the same as the Reveal All menu selection. If you have an active selection, the selection will be set as white, with the rest of the layer mask filled with black, or masked.

The sample at the left shows both the original photo, and then a Reveal All mask added to the layer. Note there is no change to the photo. In this sample, the mask edit mode is on, as shown by the closest icon to the layer thumbnails. With this icon showing, any edits we do will be applied to the mask, not the photo. If the edit mask icon is not showing, click on the mask thumbnail in the layer row to activate it.

Edit the Mask
When the mask edit mode is activated, the foreground and background colors automatically change to black and white. If you choose another color as the background or foreground color, your choice is automatically converted to the grayscale equivalent. Again, keep in mind that this does nothing to your original photo – the grayscale restriction is only for the mask.

As a simple exercise, let's add a mask to make the border pixels mask the photo with 50% transparency. Select All. Choose Select> Transform Selection and holding your ALT (Option) key to resize your selection from the center, set the size of your borders. Unless your image is square, you may want to move the sides independently from the top and bottom for an even border. Double click to set transformation. Choose Select>Inverse to select the border pixels.

Choose Edit>Fill from the main menu and specify Black and 50% for Blending Opacity. In the sample at the left, note how the selection borders are reflecting the change to the mask, and therefore the photo, but the photo remains untouched (see the thumbnail). The mask now has a 50% gray border. This is masking the photo by 50% and allowing 50% of the background, or white, to show through. If we change the background to brown and make no changes to the photo layer, the results will be as shown here. Since the mask is working on the photo layer, the 50% border will allow whatever is on the lower layer to show through.

This is quite powerful, but you really could do this with the selection tools. Squares and straight lines are great for learning about masks, but let's evoke a little more mask power. We are going to use painting tools to make the border more interesting.

Photos © Tom Thomson Photography. Used with permission.

Adding paint effects to a layer mask
I changed the background back to white for easy visibility. Activate the mask edit icon by clicking on the mask in the layer window if necessary.

This effect started with a wide border selection. Create a layer mask as above. Activate mask edit mode and fill selected area with a pattern fill (see Lines tutorial for directions on creating and defining a pattern). This creates a rectangular frame with the pattern texture allowing some of the background to show through.

To create the irregular edges, select the Pattern Stamp Tool from the Rubber Stamp tool fly-out. With mask edit activated, click along the edges of the frame to create an irregular edge. The Pattern Stamp Tool paints with the current pattern fill. You can see the effect of the new edges in the layer window sample shown above the photo.

You can also apply filters or any other paint tool to a mask. The effects are limited only by your imagination. The best way to actually become comfortable with masks is to play. If you can find an hour or two to experiment without production pressure, you will have your time back many times over in the future. Masks are great tools for automation and consistency in addition to the wealth of artistic opportunities they present.

Carry on to the next page to learn about one of PhotoShop's best features, Quick Mask. In the next tutorial (April 17, 2000), we will cover alpha channels, saving masks and importing graphics from illustration programs to use as masks.

Next page

Masks Are Easy Tutorial Index

Masks Are Easy Start
The Power of Gray
Why Bother?
PhotoShop Mask Basics
PhotoShop Quick Mask
PaintShop Pro Masks
PaintShop Pro Artistic
CorelDraw Masks
Mask Power with Fireworks