Splitting a queue to different printers based on paper size?

[athol]

I've finally taken the plunge and bought an HP 2550L colour laser
in addition to the HP 6L that I've been using for the past 6 years.

That means that I'll have two separate CUPS printers on different
machines on my network.

I use 2 paper sizes: A4 and DL (envelopes).  The 6L has a paper
feed problem with A4 (multiple pages at once) but works fine with
envelopes.  I'd like to have a printer queue that automatically
sends all DL pages to the 6L and all A4 to the 2550L.

Is there an easy way to automatically direct pages of size DL to
printer #1 and pages of size A4 to printer #2?  This could be
separate jobs or a single job containing a DL envelope and several
A4 pages.

-- 
Athol
<http://cust.idl.com.au/athol>
Linux Registered User # 254000
I'm a Libran Engineer. I don't argue, I discuss.