Hand-Blocked Paper
Hand-blocked wallpaper is printed with the same relief blocks used for cloth, one colour at a time, on paper laid out in long lengths. Between colours the run has to dry, so a paper with six colours is passed six times and hung to dry six times, which is why the method has always been expensive and why it survives only at the top of the market.
The surface is quite different from a machine print. The colour sits on the paper as a slight raised film rather than soaking in, so it catches light at a shallow angle, and the edges of each shape have the faint broken quality left by the wooden block. Distemper colours, which many traditional papers use, add a chalky bloom that a modern ink does not have.
Because the paper is printed in lengths rather than by continuous roller, the repeat is generally shorter and the registration between drops is deliberately loose. Hanging one of these papers is therefore closer to matching a pattern than to butting a seam, and the tolerances are wider than a modern paper allows.
The finish is not washable and does not tolerate steam, so it belongs in rooms that stay dry. Its real argument is depth: a hand-blocked paper in low light keeps its pattern legible where a flat printed equivalent goes dead.