>... The only time I had head clogging problems with these printers, was when I used third party inks. ...
While it may be true that, on average, third party inks clog more frequently than OEM inks, the manufacturer or type of ink is just one of several factors that correlate with this problem.
As a counter example, the used 7800 with OEM ink I purchases a year or so ago was badly clogged with the OEM inks and has never had a clog with the Carbon-6 midtone inks, which are the cheapest inks I'm aware of and, as far as I can tell, far more lightfast than the OEM color inks.
A couple of the factors in clogging, aside from infrequent use of the printer, that I'd like to point out include binders needed for glossy printing as well as the quality of the printer and its capping station.
With respect to the binders, my observation is that in a matte paper only ink the binders can be very low if not totally lacking. Carbon-6 came out of a project to make a "workable" carbon inkset for a well known watercolor painter. She wanted to be able to smear the image with a wet brush. That failed because the carbon is so fine and buries itself so well into the paper and coating that no binder is needed. With no binder, there appear to be virtually no clogs with this inkset. The glue that sticks the pigment to the slick glossy paper also sticks the particles together and to the heads. This appears to be the case whether the binder is a coating on the pigment or in the fluid base, but the latter strategy does appear to cause more problems -- although it also lowers the bronzing.
The Epson printers are getting better. The 1400 has amazed a number of us with how well it seems to resist clogging. I think a major part of this is the quality of the capping station. How well the capping station seals and thus retains the moisture has been identified as a major factor for years with those who have wide format printers.
I believe the modern Epson printers also have a teflon coating the heads to help avoid the pigments sticking to them.
At any rate, I don't think one can categorically condemn third party inks. If we're just looking at the matte paper only versions, I'd even go so far as to say that my experience is that they may clog less than the OEM inks.
Paul
www.PaulRoark.com