dye vs pigment ink

Assumption: dye is molecular, pigment is particle, which is more likely

to clog with intermitent use, 13x19 printers, Epsom, Canon, HP?

Using the same print head I'd say pigment. However you AREN'T using the same printhead and clogging really varies from model to model as much as from ink to ink.

My 2200 (pigment ink) is far less prone to clogging than my 1270 (dye ink). The only time even one nozzle clogged in my 2200 was after over 6 weeks of disuse, and cleared with one cleaning cycle. The 1270 would clog within a week, and half the time required a change of cartridge(s) to clear.

 

Perhaps the fluid in dye ink contains a binder, and the residue is gummy, whereas the fluid in pigment ink is simply a carrier with dispersent.

My experience is the same as Edward's (1280 instead of 1270).....

My experience is the same as Williams (785EPX and 700 Photo instead of 1280 instead of 1270).... :)