31 Jan
2010
31 Jan
'10
8:27 p.m.
Dave McGuire wrote:
Dedicated thermal receipt printers are nice, but
from what I've heard
they're not as reliable as dot-matrix impact printers in the field.
That seems odd to me, but I guess the heating elements dying does make
some sense.
There's one major issue with direct thermal: ink fade. Basically the
printing fades over time. Some retailers love this, because after about
8 months the receipt is basically blank -- "Sir, we'd be happy to accept
that under the 12-month guarantee, but we need a receipt -- not a blank
strip of paper."
For bonus points: heat and light make it fade quicker. Leave a
thermal-print receipt on a windowsill on the 1st of the month and it'll
be blank by the end of the month. Leave it on or near a radiator and
it'll go completely black within a few minutes.
There are also significant chemical compatibility issues. Most notably,
applying a strip of Sellotape to a thermal-printed slip/receipt causes
the ink to fade over a matter of hours (or in some cases minutes). This
is great fun in photo labs -- you have an order slip with the order
number on it, which the customer takes to the counter to pay. That's
then taped to an order docket, which is given to the lab guy to print.
Catch: tape erases the printing on the order slip, so you by the time
the prints are done, you've got a docket and no matching order number.
(Process C-41 bleach-fix fumes just serve to speed up the fading process!)
Such fun.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/