Thought it may be of interest to post up some Technical Pens

Here is the Uno ~ Made in England & these date from around 1967
They had their own nibs sizes peculiar to their own brand & stencils & did not conform to Iso Standards that all the other German Manuf's adopted

I used these mainly for lettering up drawings with a variety of Uno Stencils

Generally they were not as sharp a line as Rotring / Mars Staedler / Faber Castell etc but were still acceptable

These were also more labour intensive in applying Ink & cleaning & therefore not as convenient ~ but as can be seen the design was actually more efficient & outlasted all the other nibs from the likes of Rotring. These nibs can still work whereas all other Iso nibs clogged overtime & were just thrown away.

I have one something like that. Not as fancy but the same principle. Here is a Christmas present from my Mom and Dad. I am told (and as on the box) it is for map drawing.