Arthur Entlich said:
These generalizations are just that. Just about every Epson and HP printer
model use different ink cartridges holding differing amounts of ink. The
Epson inks should, in theory, go further per liquid measure, because they do
not need to be boiled or heated to be printed with.
This is a bit misleading - the ink is not boiled away in the HP design. A tiny
layer of ink is vaporized, pushing the ink droplet out the nozzles. The vapor
bubble very quickly collapses back into liquid inside the printhead.
The pages per ml will be more strongly impacted by the dye (or pigment) loads,
the dot gains of the particular ink and media, the print modes (how the ink is
applied, how it is layered to make millions of colors, etc). Servicing also
has a large impact on real pages out. Different systems have different method
and requirements for the amount and frequency of servicing required.
From the customer standpoint the important factors are not drops per ml but
pages per $ (or insert local currency here) and perhaps pages per cartridge
which takes into account the inconvenience of having to replace cartridges..
Currently this is a bit difficult to compare without some homework, as
different manufacturers use different test methods, samples and definitions.
One manufacturer specifies a 5% page, but the fine print notes that the
8.5"x11" page has 1" borders on all four sides - the are printed at 5% is only
a 6.5" x 9" page. There is currently an ISO standard being developed that will
allow more direct comparisons of page yields, with controlled standards and
reporting methods. This effort is currently expected to be ratified by the end
of 2005.
Regards,
Bob Headrick, not speaking or my employer HP