Fill, Stroke, Gradients & the Appearance/Style Panels

Chapters 3 and 4 covered drawing shapes — custom paths and regular geometry alike. Every one of those shapes has so far been an outline with no real appearance yet. This chapter gives them one: fill, stroke, and gradients, controlled through a panel that goes by a different name in each application but does the same underlying job.

Fill and Stroke: The Two Basic Appearance Properties

Fill is the color (or gradient, or pattern) applied to a shape's interior — which is exactly why Chapter 3 emphasized closed paths, since an open path has no bounded interior for a fill to occupy. Stroke is the color and width applied along the shape's own outline path itself. A single shape can have a fill, a stroke, both, or neither, and each is set independently.

Solid Colors, Color Models & Swatches

Both applications support the same basic color models — RGB for screen work, CMYK for print work — plus a swatches panel for saving and reusing specific colors consistently across a project, exactly the same practical need Raster Editing Fundamentals' own color-mode material addressed for raster work. Consistency matters even more in vector work, where the same logo or icon often needs to reuse an exact brand color across many separate shapes.

Stroke Weight, Cap, and Join

Stroke weight sets how thick the outline is. Cap controls how a stroke's open ends are finished — butt (a flat cut-off), round, or square (extended slightly past the endpoint). Join controls how a stroke behaves at a sharp corner — miter (a sharp point), round, or bevel (a flattened corner). These options matter more than they might first seem: a thick stroke with the wrong join can look noticeably different at a shape's corners than the same stroke with a different join setting.

Gradients: Fills That Transition Between Colors

A gradient fill transitions smoothly between two or more colors across a shape, rather than filling with one flat color. Linear gradients transition along a straight line; radial gradients transition outward from a center point. Both applications let a gradient's individual color stops be repositioned and recolored, and let the gradient's own angle or center point be adjusted directly on the shape rather than only through a dialog box.

Illustrator's Appearance Panel vs. Inkscape's Fill and Stroke Dialog

Illustrator manages all of this through its Appearance panel, which does something genuinely distinctive: it can stack multiple fills and multiple strokes on a single object, each one layered on top of the last, with the stacking order directly affecting the final look — the same "ordered stack, order matters" idea this site's own Audio & Video Production courses kept encountering in different forms (layers, Sources, timeline tracks), showing up here again inside a single object's own appearance. Inkscape's Fill and Stroke dialog covers the same fill/stroke/gradient properties but as a single fill and single stroke per object, without that same multi-layered stacking model.

Hands-On Exercises