Try Pigma Pens from StatLabs. They have a very fine point and seem to work
well.
Mequita Praet

Donna Sitrin wrote:

> Hello!
>
> I know this is an age old question, but we are having increasing
> difficulties with our cassette markers (the usual permafrost pens).
>
> They have modified their formula, and the pens are worse than ever.
>
> Does anyone have a marking system or knowledge of marking pens that are
> solvent and paraffin resistant?  We have tried "Sure Mark" pens, but they
> have a broad point and we write many designations and specials on the
> cassettes.  The broad point limits the space we have for this.
>
> Thank you for your input.
> Donna in Denver
> Unipath, LLC