Question about rapidographs

[Andrew Schlageter]

I am a huge fan of rapidograph technical pens, especially because of their accurate and consistent lines. However, the thinnest size I have successfully used is the 4x0 (.18mm).  Many people argue about the 6x0 (.13mm), saying that it's lines make what you draw too faded.  I disagree, but have had huge problems with that size.  Although I regularly cleaned with the bulb and cleaning solution, and used ultradraw ink, my 6x0's had bad problems with clogging.  Some clogged within two days although I used them regularly and kept the ink flowing, some survived to be cleaned once just to clog a day later, and a couple actually clogged within hours even when capped.

I'm fine with the 4x0, but I just want to know, has anyone had any consistent success with the 6x0's? and if you have, did you have to do anything out of the ordinary (ie different ink, different cleaning tactic)?    

[Angelina Whittaker Cook]

I used these pens when I was working as a technical illustrator (early 6o's) and our biggest problem was the clogging. We used them in the drawing office in order to keep a consistent thickness of line mainly. Sad to see that the manufacturers have not solved this problem! I as an artist would not bother with them as the line is too mechanical. Nowadays artists have a wealth of tools to choose from.