Most of the Tibetan books that survive in quantity were printed, and printed from carved wooden blocks rather than from movable type. A page was written out, pasted face down on a prepared block, and cut away so that the letters stood in relief and in reverse; the block was then inked and pressed against paper, and could be stored and reprinted for centuries.
The method suits the script. Tibetan writing stacks vertically, with superscripts, subscripts and vowel signs assembled around a root letter, so a syllable is a two-dimensional object rather than a row of separable pieces. Movable type has to cut every combination or accept ugly compromises; a block cutter simply cuts what the calligrapher wrote.
Large printing houses were established at monastic centres from the fifteenth century onward, and the great eastern establishments of the eighteenth century produced editions of the canon whose blocks were held as an institutional asset and reprinted on demand. The printed page keeps the format of the manuscript it descends from: long, narrow, unbound folios stacked between boards, written on both sides, with the volume identified by a letter rather than a number.
The scribal hand behind the block is dbu can, the headed script, because it is the formal hand and because its separated, upright letters cut cleanly. Cursive Tibetan is written and not printed.