Thursday, 8 May 2008

Changing the purge image file I use with MIS Autoprint

In a previous posting I have gone through my experience with setting up and running MIS Autoprint. I have recently changed the purge pattern I use – this posting tells why I felt I needed to and what I changed it to.

In my previous posting I have explained what MIS Autoprint does and how it fits into the nozzle clogging avoidance scheme for my Epson 4800 inkjet printer.

The whole point of using Autoprint it so “exercise” all the printer’s ink channels more thoroughly than just printing frequent nozzle checks alone manages.

I thought I was doing this by using the 8 channel purge file supplied by MIS, but recently I found a printout of it printed with the LM channel completely missing, as confirmed by the automated, via Harvey Head Cleaner, nozzle checks printed out in the morning before and an hour after the purge file automatically printed.

Below is a scan of what the 8 channel purge print looks like when all nozzles are running perfectly:

Below is a scan of what it looked like with the LM channel completely missing (but the M channel was perfect):

The M & LM ink blocks have tuned blue with no sign of M in either, and the blacks (K, LK & LLK) have taken on a bit of a green’ish tint; the Y, C & LC look normal. This tells me that whatever is going on the purge print is not faithfully using all the ink channels as I thought it was – which rather misses the point of the whole exercise. It is possible that the paper setting affects what inks the 4800 uses, but I don’t have any way of checking that without losing a channel again – which I have not intention of doing deliberately. Currently I use copier paper in the printer for these maintenance prints with the media type setting set to "Plain paper" in the pinter settings.

So now I have swapped the MIS 8 channel purge file – if you want to know how to do this then look at an earlier blog posting here – for one I made up myself (see below). This is derived from a couple of colour patch files from Permajet used for creating ICC profiles of their papers; each set having 936 patches. While I have no proof that they are any better
at exercising all the ink channels than the simpler 8 channel purge file from MIS, it seems logical to think that it has a better chance.

If/when an ink channel goes missing I will check out the results and post them.

I have done that now and here are the results

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