If it's compatible with the R280, I have some software that prints direct (i.e. bypasses gutenprint) in order to 100% control drop size. http://www.delorie.com/pcb/pbm2escp2.zip
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Re: [Homebrew_PCBs] Gutenprint configuration for print density, drop size etc for Epson printers?
2013-02-07 by DJ Delorie