Decorative Finishes
Decorative Finishes
This domain tests special-effect finishes: their materials, tools and sequence. Questions ask which technique produces a named effect and what controls open time and texture.
Techniques and materials
- Stippling: a stipple brush or sponge is dabbed into a glaze to give a fine mottled texture.
- Sponging and ragging: a natural sponge or cloth removes or adds glaze to create broken colour.
- Dragging: a dry brush is pulled through glaze to leave fine parallel lines.
- Marbling: a ground coat is overlaid with glaze, veins are drawn with a feather or brush, and the whole is softened and varnished.
- Wood graining: a ground coat plus scumble is combed and overgrained to imitate figured timber.
- Limewash and distemper: traditional porous finishes for masonry and interior walls.
- Metallic and pearlescent finishes need a compatible clear topcoat to prevent tarnishing.
Open time
Glaze work depends on open time. Scumble glaze can be extended with a recommended extender, but too much thinner makes it run and lose texture. Work in small areas and keep a wet edge.
Worked example
A decorator wants a soft dragged finish on a panel. The glaze is mixed and tested on a sample board. The brush is barely loaded and pulled in one continuous stroke from top to bottom. If the glaze is too wet, the lines merge; if too dry, the brush skips. The reasoning is that dragging records the brush tracks, so glaze viscosity and loading control the result.
Traps
- Applying glaze over an unsealed ground and getting patchy absorption.
- Working a large wall in one go and losing the wet edge.
- Adding too much thinner and turning a drag into a run.
- Skipping the protective clear coat on metallic finishes.