Criteria we're looking at:
1. Reliability: The printers need to be very low maintenance and be able to cope with dusty environments.
2. Cost: Obviously, costs need to be kept as low as possible. No cap on the cost of printers precisely, but the net cost per page over time is critical. More expensive printers with cheaper and standard consumables are likely to be preferred to cheaper printers with expensive consumables.
3. Ink duration/lifespan: While all sites would be printing at least weekly, the amount actually printed may vary between no more than a few pages each week to several hundreds of pages. This means that whatever ink/toner cartridge/etc needs to have a long shelf life as well as lifespan. Zambia is not terribly hot, but has a humid rainy season and no climate control can be expected.
4. Low power consumption: As stated, ~15% of sites (and growing) are operating only with solar panels.
5. Quality: The quality of the printing can be quite low. Must be legible but can be ugly. No need for color. However, the pages/text need to have approximately a 5yr duration before the ink is unreadable.
6. Label Printing: There is also a need to print labels for specimens (freezer tolerant) and for drug dispensations. This may well be a different product, and early implementations will be in higher volume facilities that might not be as sensitive to power, but there will be a need for a low-power version eventually.
Our instinct is that dot-matrix printers would fit the bill nicely, but the options there seem to be limited and the long-term sourcing of supplies (ribbons, perforated paper) isn't entirely clear. What other options would the Slashdot community recommend?