Step 1: Select the Flood Select Tool
First, go into the Pixel Persona.
In this workspace, Affinity has a new set of tools on the left side. Select the Flood Select Tool.
Step 2: Adjust the Flood Select Settings
Before making a selection, turn on Contiguous. Contiguous will allow you to only select the white background, not any white areas inside of the dog, like the white pupils of his eyes.
In addition to Contiguous, turn on Antialias. Antialias will make the selection smoother, preventing jagged edges.
Step 3: Make the Selection
With those settings turned on, click anywhere in the background, and Affinity will make a perfect selection.
Step 4: Remove the Background
With the selection finished, you can remove the background by pressing Delete on your keyboard.
To remove the selection outline, press Ctrl + D (PC) or Command + D (Mac).
Step 5: Save the Image
If you want to save this image with the background removed, go to File, then to Export.
From here, select PNG, not JPEG. Then press Export.
Now you know how to remove a white background in Affinity Designer. 😊