Lichte Initialen (“open initials”) were drawn by Emil Rudolf Weiß in 1935 and later assigned to his Weiß-Gotisch (Bauer, 1936). [Moorstation] Shown in a specimen as Initialen zur Weiß-Gotisch. [Typografie.info] It’s not clear if they were produced as metal type, as galvanos, or in some other form.

Digitized by Manfred Klein as Weiss Gotnitials (2005, used for sample). The lowercase (not shown) has caps with one half of the open letterforms filled in.