I've had good luck using omnicoat as an adhesion layer over Cr,
followed by the standard SU-8 formulation (not 2xxx or 3xxx).
Omnicoat is available from Microchem.

This will work fine as long as your SU-8 won't have long-term exposure
to any weak base solutions (such as a positive photoresist developer)
which will remove / undercut the omnicoat (and release your SU-8).

- Kevin

On Mon, Feb 21, 2011 at 11:35 PM, marlon menezes  wrote:
> I am currently using SU 8-2xxx series but are having problems with adhesion on
> Cr coated substrates. KMPR is advertised to be superior to SU 8 for its
adhesion
> to metals. However, I have not seen any literature that talks specifically
about
> Cr. I checked with Microchem as well with no luck. Any info would be greatly
> appreciated.
> Regards,
>
>  Marlon