The Fill command and patterns in Paint by Zaweba
Edit > Fill in Paint by Zaweba fills with colours, patterns or scripted brick, weave and spiral fills, and Define Pattern checks seams first.
The Fill command is easy to dismiss as a basic tool, but in Paint by Zaweba it does a lot more than pour in a colour. Edit > Fill, or Shift+Backspace, fills a selection or layer with colours, patterns and a set of generated patterns, with control over how the fill mixes with what is already there.
What it can fill with
The plain choices are the foreground colour, the background colour, any colour you pick, black, 50 percent grey and white. Black and white are quick for masks, and 50 percent grey is the standard starting point for a dodge and burn layer in Overlay mode, since mid grey has no effect in that mode until you paint on it.
Pattern fills with a pattern from your library. Then there are scripted patterns, which are generated on the fly rather than taken from a tile: brick, cross weave, random, spiral and symmetry. Brick is good for walls and tiles, cross weave for fabric, random for scattered textures, spiral for swirling backgrounds and symmetry for mirrored, kaleidoscope-like designs.
How it mixes in
Mode is the blend mode of the fill, so you can multiply a pattern over a photo to add texture, or screen a colour to tint highlights. Opacity sets the strength. Preserve transparency fills only the pixels that already have content, leaving transparent areas empty. That last one is very useful: fill a text layer or a cut-out with a new colour or pattern without filling the empty space around it.
Define Pattern
To make your own pattern, select an area and use Define Pattern. The dialog shows a 3 x 3 preview of the tile repeating, plus a half-tile offset view. The offset view moves the tile's edges into the middle where you can see them, so any seam where the left edge doesn't match the right, or the top the bottom, shows up straight away.
If you see a seam, fix it before saving the pattern. Wrap-around mode is ideal for that: it tiles the canvas so you can paint and clone across the edges until the join disappears. Then define the pattern again.
Patterns go into the Patterns library, where you can keep and reuse them. They work in the Fill command, the Paint Bucket and anywhere else the app uses patterns.
Define Brush from Selection
From the same family of commands, Define Brush from Selection turns a selected area into a brush tip. Select a texture, a leaf, a splash or a stamp-like shape, define it as a brush and you can paint with it using the full brush engine. It is a quick route to custom stamps and texture brushes.
Jobs it does well
Backgrounds: a brick or weave scripted pattern on a new layer, with a colour overlay, makes a textured background in seconds. Texture on photos: a subtle pattern in Overlay or Multiply mode at low opacity gives a canvas or paper feel. Recolouring: Fill with preserve transparency changes a layer's colour completely while keeping its shape. Masks: black, white and grey fills set a mask quickly.
Tips
Fill on a new layer when you can, so you can change the blend mode and opacity later or delete it. If the edges of a pattern look soft or blurry, check that the tile size works with your document's size. For a patterned area that you may want to change later, consider a Layer Art effect instead of a fill, since live effects stay editable.
Remember the shortcut. Shift+Backspace opens the Fill dialog with your last settings, which makes repeated fills quick in Paint by Zaweba.
