Rod wrote:
e.g.
http://www.staedtler.co.uk/Lumocolor_CD_DVD_pen_uk.Staedtler

I *think* that says rated to "ISO 554" - not that it can last 554 days!


OK my mistakke, several days most dry safe pen manfacturers claim under
ISO 544 (Standard atmospheres for conditioning and/or testing -
Specifications)

Usual ISO problem. Can't find a download link for that doesn't want a
credit card number. Chances of a prospective pen purchaser actually
viewing the standard before making an informed purchase is slim ...

--
Adrian C