While I really had not planned to test any of the pens from the recently unearthed vintage drafting sets, the temptation was a bit much with these pristine fine pens staring back at me begging to be used after probably decades in storage.
The translucent pen point housing clearly showed when the drawing ink had reached the tubular pen point and we were ready to draw!
Using the template adaptor to keep the technical pen point perpendicular to the drawing surface. Noticed that I used a fresh bottle of Rapidograph Ultradraw Black India ink to fill the pen rather than the old Higgins ink bottle from the pen set (see the end of this post for the full explanation).
Sample doodles on Canson bristol.
Pen point removal tool, adjustable adaptor, and 0.7 mm pen test
Whenever you get a vintage technical pen set remember that the included ink bottle probably should never be used within a technical pen. Keep it as a collector's piece, but do not ever even think of filling any pens with it. The ink components often separate and precipitate to the bottom of the bottle. Shaking does not restore the proper viscosity, and the sediments might clog the pen points. Even if the old ink does not look severely faded, the safer approach would be to get a fresh bottle of ink if you decide to put the pens through some doodle tests. Once you are done testing them, you would do well to remember that the pens should be flushed, thoroughly cleaned and dried before storing them away for long periods if you wish to use them ever again. Dried ink is notoriously difficult to wash off if allowed to settle within the interior channels of the tubular pen points. These master pieces of German engineering still work great, but they do require lots of maintenance and frequent cleaning. Thus it is quite understandable that they have gone the same way as NASA and the space shuttle program. Unlike graphite drafting tools that can be used pretty much forever, technical pen sets would likely see their useful active life further limited when manufacturers stop making ink for them. So enjoy them while you can.