Learning Paths

Quick Mask Mode

The Quick Mask Mode allows you to modify a selection by painting it. I often use the Quick Mask Mode to clean up a current selection by adding or taking away from the selection.

It is best to start by making a selection using a selection tool such as the Quick Selection Tool. Any tricky bits of the selection that can’t be improved upon with a selection tool, when then it’s perhaps time for the Quick Mask Mode.

In the image below, I have selected the post box using the Quick Selection Tool. Because the sign and the post box share the same colour black, it is not possible to select just the black area of the post box without selecting some of the sign. There are also a few other areas I would like to tidy up to.

To turn on the Quick Mask Mode by clicking on this icon at the bottom of the Tool Bar.


The area that  was selected looks normal and the unselected area is covered with a red colour overlay. By default, the Quick Mask Mode is a 50% opaque red. With the post box being red too, lets change the colour of the overlay so its easier to see.

Double-clicking on the Quick Mask Mode icon  will bring up the Quick Mask Options panel.

First, lets change the colour. Clicking on the current colour which is red, brings up the Color Picker. Using the Vertical Color slider (highlighted in orange) and clicking in the Color Picker (highlighted in green) area allows you to choose a new colour. Click the OK button.

In the Quick Mask Options panel other options can be changed:

Opacity: This is the strength of your chosen colour. 100% opacity will mean the colour is solid, so you can’t see through the colour. Anything less than 100% will mean you can see through the colour. I like to keep it around 50% so I can see the unselected areas of the image.

Masked Area and Selected Area: These toggle options allow you to control what areas the colour overlay gets applied to. With Masked Area selected, the colour overlay gets applied to the unselected areas. If  Selected Area was chosen the colour overlay will get applied to the selected area.

Choose your options then press the OK button in the Quick Mask Options panel.

Click on the Quick Mask Mode icon  to see the colour overlay again. A quick way to turn the Quick Mask Mode on and off is the Q key.

 Adjust the selection

To adjust the selection we need to adjust the colour overlay. Remember the colour overlay represent unselected areas, the areas that don’t have the overlay applied are the selected areas. To adjust the selected and unselected areas we can use the Brush Tool, which you will find in the Tool bar.

If you take a look in the Tool bar you will also notice that the foreground is now set to black and background colour to white.

White is used to add to your current selection and black is to remove from the current selection. Pressing the X key is a quick way of swopping between black and white.

Right-click on the image with the Brush Tool, this will bring up options for the brush. The Size and Hardness (hardness to softness) of the brush can be adjusted. Because the post box has hard edges I have chosen a high Hardness value. You will need to keep on adjusting your brush settings as you paint, particularly the Size. Here are the initial settings I have chosen:

Painting the selection

To remove from the selection, ensure that you are painting in black and paint out areas that you don’t want selected. Press the X key to swop to white so you can add to your selection. Keep toggling the Quick Mask Mode off and on by pressing the Q key so you can see how your selection is updating.

In the below example I have some of the sign selected (left image), so I have painted it out using black (right image).

After you have finished modifying your selection in the Quick Mask Mode always ensure you come out of the mode by pressing the Q key

Below is a before (left image) and after (right image) screenshot of the image and selection.