[dbelford]

In another comment you mentioned easy scaling in a photocopier. And cylinder714 linked to a description of iso-paper that mentions an ISO (ISO 9175-1) for pens.

Is there a term or place to search for pens sets that scale with A*/B* paper? Using the ISO or "technical pen" doesn't return obvious matches (from my US based search at least).

[Symbiote]

I searched "ISO drafting pens" and had several results, although none from the US or Canada. Wikipedia lists some manufacturers, and here are some online shops from my first couple of pages of results.

I've never used the steel nibbed pens. My grandfather was a draughtsman, and had a complete set, but as I understood it (age 10-ish) they were delicate and needed to be used carefully. I wouldn't buy a complete set on a whim :-)

https://en.wikipedia.org/wiki/Technical_pen

https://www.rotring.com/pens-pencils/technical-pens/isograph...

https://www.staedtler.com/intl/en/products/technical-drawing...

https://draftex.com.au/collection/pens-markers-inks/technica...

https://www.faber-castell.eu/products/TechnicalDrawingPenTG1...

(There were also Indian websites, so I'll bet there's China/Aliexpress too.)

[dbelford]

Wonderful, ISO-128 is exactly it and the wiki explains it perfectly. This seems like a fantastic sizing for pen sets.

The 0.10, 0.13, 0.18, 0.25, 0.35, 0.50, 0.70, 1.0, 1.4, and 2.0 scale with √2. I couldn't tell if other sets were just rounding or dropping the hundredths place. The rotring and staedtler both offer sets in those increments. I suppose this is just common knowledge to those who need it.