Two early specimens of Rudolf Koch's typeface Prisma

KLINGSPOR (Gebr.) Schriftgiesserei. Prisma. Eine neue Versal-Schrift nach Zeichnungen von Professor Rudolf Koch.  [together with]  Prisma. The new design of Rudolf Koch. Offenbach a.M. & London, c.1930-31. 2 vols. 8vo & landscape 8vo. Pp.[8] + 12 loose pieces of ephemeral printing in pocket at end; large folding title, pp.[8] + 9 pieces. Orig. semi-stiff boards. Printed in Germany at the foundry, in black and colours. The specimen in English slightly age-embrowned and very slightly worn. Uncommon. Koch's extraordinary decorative exploration of his sanserif Kabel. Sold.