Labor Intensive

from "Byzantium Preserved," by Patrick Brogan, found in Istanbul: The Collected Traveler, collected by Barrie Kerper:

The lower parts of the walls throughout the [Church of the Savior, or Kariye Camii, in Istanbul], and particularly in the main body, are covered with marble panels of great splendor. … The Byzantine masons would select blocks of stone of striking color and markings, preferring ones with wavy lines across them.  They would cut the blocks vertically into very thin slices and then open them like the pages of a book.  The right-hand slab would then present a mirror image in perfect symmetry with the left.  If the block was smooth enough, the masons could sometimes cut two or even four pairs of slabs, and the pattern ripples in waves across a wide expanse of wall, thus bringing discipline and order to the irregularity of geology.  Samuel Pepys, in Restoration London, described how marble was cut, by means of a technique that had not changed since classical times.  A groove was chiseled along the top of a block of stone and filled with sand.  Two men then cut into it using a cord as though it were a two-handed toothless saw, grinding away the stone with the sand.  About two inches of marble a day can be cut this way.  Thousands of days' work must have gone into cutting the marble panels at the Church of the Savior.

 Imagine.