Disbanded sketchbook of 80 pages of off-white medium-weight wove paper 290 x 240mm in ten signatures of eight (with or without front and rear endpapers). The width of many pages varies up to 5mm depending upon how the drawing was removed from the spine. The sketchbook spans 1950 and 1951 and was disbanded at an early date. Some pages were dated contemporaneously and others later; there is no consistency, though pages with higher numbers tend to be dated 1951. The drawings are numbered 1-160 upper right on the recto and upper left on the verso, the numbers being circled up to p.47. Two pages HMF 2644 and 2646, numbered 35 and 47 uncircled, have always been considered part of this sketchbook and are placed immediately following the last numbered page. Some pages are unaccounted for, but six pages HMF 2686, 2688, 2690-2692 and 2694, which are overmounted or known only from photographs, could be from this sketchbook and have been added at the end of the sequence.

One drawing HMF 2631c is known to have been mounted in Heads, Figures and Ideas 1958; see also Sketchbook 1950(SKB 56), Unesco Notebook 1954-57 (SKB 60), Heads, Figures and Ideas Notebook 1955-56 (SKB 59) and Heads, Figures and Ideas Sketchbook 1956 (SKB 62).