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April 17th, 2013, 02:51 PM
Ok, I just got off the phone with a gentleman at Epson support. He was very helpful and said they have received a lot of calls about issues printing over existing prints. He explained this is only an issue with the 7890/9890, 7900/9900 and 4900 printers because they added an optical paper sensor (called the PW Sensor) to the print head. This sensor is not in previous or newest printer models, as they realized this is an issue. This sensor has many responsibilities, including checking the alignment, paper size and skew. Disabling the paper size and skew check in the printer menu will not fix or effect the problem, and they explained this sensor can not be disabled, disconnected or tricked. The optical paper sensor constantly reads the paper during printing, so the top or side white paper margins don't matter, if it sees what it thinks is the end of the paper, it will stop printing. Sometimes it will see printed area and stop printing, but other times it will not see the print and successfully print a second layer over the entire sheet, so the results are not consistent (as we have come to realize after much testing).
Prior to releasing Piezography for these printer models, our test results were great and this printer sensor issue wasn't discovered until later. Unfortunately, we have no control over the printers, nor can we foresee and avoid all possible issues, though we do put a lot of time into researching and testing our products prior to release, and continue to use our carts and inks every day to ensure the highest quality products and knowledge of our products. Epson has recognized the problem this sensor is causing, and has abandoned it for their new printers. Unfortunately, their new SureColor S-series printers are MUCH more expensive than the previous models, and it's very possible they would not be supported by QTR.
At this point, the solutions are:
1. Get a second printer (I recommend a 7600/9600, 7800/9800 or 7880/9880) to use as a GO coating machine, which will ultimately double your production to have one printing ink and the other printing GO (we have a 7600 set up as a GO only printer, and it works great). The GO printer should be in ok condition, but doesn't need to be in perfect (as you want for the ink printer). As long as it has at least one good print head channel, you can use it or GO printing.
2. Manually spray coat the prints using Hahnemuhle, Lumijet or a similar glossy protective spray for inkjet. The drawbacks of this are that you need a very clean and well ventilated area to spray, and it takes some practice to get a nice even coating.
3. We have already spent a great deal of time trying to find a way to print GO at the same time as ink. In past attempts, we got close, but there was always some sort of imperfection that were not happy with, and discovered the second pass GO coating over dry ink produces the best results, so abandoned the simultaneous printing idea... We will attempt this idea again, though are not hopeful it will work, and would not be able to do this for all glossy papers, because the GO limit may ultimately different from paper to paper. Printing GO at the same time also increases the overall ink limit and can effect the print detail. As perfectionists and the developers of Piezography- we require crisp detail, even gloss finish with no bronzing (we are not easily satisfied), so we will spend some time on this possibly as early as tomorrow, but can't make any promises that it will work to our satisfaction in order to offer as a solution for our customers. [/i][/i]
