Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., "B. Alex Pettit Jr." 
<a_pettit_jr@y...> wrote:
> I have been using  sets of user filled carts with MIS FSe for about 
a 2 months with very little printing- but with never a cleaning cycle 
required. A head test yesterday was perfect. 
> I live in Florida ; I keep the printer covered (to keep the cat out 
!). 
> 
> I am wondering if a good vinyl cover over the printer might 
stabilize the humidity and minimize some of the printing problems 
being experienced by others ???  Could then get one of the temp/humid 
units from Radio Shack and keep the humidity at some level (70%) via a 
damp sponge in a small plastic bottle, etc....
> 
> Best,
> Alex

Actually, this has been recommended by people at various times in the 
past, you almost got their procedure exact. Most get an oversize cover 
 and put a dish or bowl of water under it. I disagreed with the 
approach and never tried it because I couldn't get around a few 
issues:
1) the smaller the volume humidified, the harder it is to stabilize. 
If I wanted to target 38-45%RH for example, it is easier to do in a 
large room then in a display case because variations would be absorbed 
by the larger air mass (just my own personal reasoning, a musuem 
curator may have a better handle on this).
2) Any hygrometer placed under the tent would be more likely to be 
innacurate (not made to measure in a small space).
3) Condensation on the printer is more of an issue which could 
prematurely upset the electronics (again my opinion, I don't know how 
one would go about proving or disproving this without risking 
printer).
4) When the cover is removed for printing, there would be a large 
change in environment suddenly. However, I have to temper this 
statement with the rule of thumb we used when I tested products for 
HP....generally in an average room you have to allow 24 hours for any 
internal humidity level INSide a product (and the hygrometer) to 
stabilize. We had chambers we would test products in and we waited 1 
1/2 hours for temperature stabilzation but 24 hours for RH 
stabilization when torture testing. A small space (suddenly removed, 
i.e. cover whisked off) I guess would equalize to the surrounding room 
more quickly, but I don't know at what rate.

Yet people do use this method so it must have some validity.
I don't think I'd take it as high as 70%RH. 40-50%RH seems quite 
adequate for my printer and Jon Cone hinted that high levels of 
humidity were also detrimental to printing.

Alex, you are another carefree printer! So two people with low 
humidity in or near Colorado have nil problems and a high humidity 
person has no problems also.

I am beginning to suspect that there is more variation printer to 
printer within the same model than I realized. Mine may just be more 
sensitive to environment. Or maybe it's just my perception, 
exagerating the problem as I am rather gunshy of toasting another 
printhead and tend to be conservative in my babying my 1280..
Jim H.
Jim H.