As I responded to Bigraph in this post What's on your desk right now? - #1112 by majkycz_y, I think it’s more likely that Bigraph produced for Staedtler (?), because I’ve only seen Staedtler in 0.3 and 0.5 mm, while Bigraph comes in all three widths and even with a full-slide sleeve (Bigraph Super S). What do you think?
Delightful sub-collection! To add a little facet to the story, I think Bigraph models were acquired and rebranded in Italy by Norex; the “Norex Micromina” series offered 0.3, 0.5 and 0.7 models — if I remember correctly, not with the coloured grip area, though: only in plain metal and black grips — and the 0.5 model for sure could be available in fixed sleeve, half-slide, and full-slide sleeve.
Its characteristic tactile feeling is quite unique, and is due to what I would call “minimally non-trivial” surface finish; this hairline striping is something available, with different degrees of “roughness”, only in a very limited run of pencils: first coming to my mind are the rOtring Fineliner S (502-155), the Faber-Castell DS-45 (and maybe the DS-75?), the Staedtler Microfix SL, and a few others — not sure the “faux-grain” of the Newmann woodgrain drafter is in this category, but boy it is close.
Also, check out the similarities between the bigraph Super 05 S and this rotring pre-fineliner S model, especially the nosecone design:
I suspect that these were all manufactured by the same plant, but I don’t know enough about bigraph’s operation to be confident that they were the ultimate maker.
Bigraph had a lot of items for engineering drawing (drawing bords, lettering devices, rulers etc.) as well as office supplies (writing pads, staplers, punches etc.). I therefore think it’s possible that they manufactured some items themselves and purchased all the others, including the mechanical pencils (just like Nestler).



