
the first time I saw a draft where the diagonals did not line up.
citation:
“This cannot be attributed to a fault in the use of the pedals, because the reproduction is constant, but to an intentional idea of the weaver’s due to a cause we do not know.
This rhombus may be called <twill based,> of (3.1,3.2, 1.2), which comprises
12 threads and 12 pick in the evolution cycle and needs for its production
12 shaft, operated by twelve pedals. The union ol the pedals to the shalt is done according to the twill base .” Mantilla de los Rios ICCROM library 20170922141234, 1973

left: The Assumption of the Virgin, 1577–79
Oil on canvas; 403.2 × 211.8 cm (1583⁄4 × 833⁄4 in.) The Art Institute of Chicago, Gift of Nancy Atwood Sprague in memory of Albert Arnold Sprague, 1906.99
Xray image courtesy of the Art Institute of Chicago
right: The Disrobing of Christ, 1577–79.
Oil on canvas; 285 × 173 cm (1123⁄16 × 681⁄8 in.). Toledo Cathedral.
source Xray image: Alba Carcelén, Laura (2015) Los soportes textiles utilizados por los pintores españoles a lo largo del siglo XVII: contexto histórico y estudio técnico a través de la radiografía. [Thesis]


