Decorative Finishes and Wall Coverings
This domain tests special-effect techniques - stippling, sponging, ragging, dragging, marbling, graining, stencilling and texture - plus wallpaper types, pattern matching and hanging procedure.
Decorative techniques
Most effects use a base coat plus a translucent glaze or scumble kept open with a retarder. Stippling dabs with a stipple brush for a fine mottle; sponging uses a natural sponge; ragging and rag rolling lift glaze with cloth; dragging pulls a dry brush or flogger vertically for a linen look; marbling veins with a feather while wet; graining reproduces wood using a comb and over-grainer; stencilling applies colour through a mylar stencil with a stipple brush and almost dry paint.
Wallcoverings
Types: paper, washable vinyl, fabric-backed vinyl, non-woven (paste-the-wall) and foil. Pattern match is stated on the label as straight, offset (staggered) or random, with a repeat in millimetres. Walls are sized or primed first; a plumb line is struck about 500 mm from the corner; paper is pasted, booked, hung, brushed out, and joints are butted, never overlapped.
Worked example
A room has a 16 m perimeter, 2.7 m walls and a 0.32 m repeat. Roll is 0.53 m × 10 m. Drops needed: 16 ÷ 0.53 = 30.2, so 31. Cut length per drop: 2.7 + 0.15 trim = 2.85 m, plus repeat allowance. Drops per roll: 10 ÷ 2.85 = 3. Rolls: 31 ÷ 3 = 10.3, so 11 rolls. The reasoning is that the repeat forces waste at every join.
Traps that cost marks
Overlapping wallpaper joints; pasting a paste-the-wall non-woven; hanging on unsealed plaster; forgetting the repeat allowance; stencilling with a wet brush, causing bleed.