Posted by Tony Martin on 7th Dec 2016
My wife makes the best brownies. They are not just good, they are spectacular. The right combination of chewy and crumbly, and very, very chocolaty. She doesn’t make them that often and usually reserves them for special occasions (you can have too much of a good thing, I guess). A week or so ago, she rolled them out for a family birthday party and they were not quite the same. Don’t get me wrong, they were still delicious and the serving plate emptied within minutes, but there was something just a little changed about them; the texture was slightly different and may be not quite as chewy. My wife noticed this as well and, later in the evening when everybody had left, she brought it up. We discussed what could have changed – were the ingredients the same? Were they cooked at the same temperature and for the same time? It was then that we realized that this was the first time she had made them using the new oven we had recently installed. So there it was, the unknown factor that had been introduced and had thrown off the end result a little. Not much, but enough to be noticeable to us brownie connoisseurs. A few days later she made them again, adjusted the baking time down by a few minutes, and, voila, everything was good again in brownie heaven.
What has all this got to do with inkjet printing? Well, it occurred to me that this brownie incident serves as a good analogy for printer work flow and color management, and how by changing one small thing, including temperature, can affect the final outcome of a print. Let’s make a comparison between baking and inkjet printing. You have the ingredients – for brownies, you have the flour, the butter, the chocolate etc, and for printing you have inks and the media. Next you have the brownie recipe which lists the amount of each ingredient, and for printing you have the color software settings or color profile. Finally, for baking brownies you have the oven and in printing you have the actual printer. It’s pretty obvious that if you change any one of these items then the results will be different, as we found out with brownies and a different oven. If you change any of these items when printing (the inks, media, color settings, printer) then the printed output will also likely be different. For instance, changing the media brand you use will affect the print, even if it is a change from one similar media type to another. It may be a subtle difference but it will be different. This is why many inkjet printer users invest in color profiling equipment so that they can maintain a consistency in color over a range of different media types and printer models. I am sure that most readers of this article know all this already but, what many people don’t realize is that temperature can greatly affect the inkjet printing process and that keeping environmental constants in place will help you eliminate problems both with the printer and your finished prints. Here are a few tips.
1.Always locate your printer in a stable, temperature controlled environment. Like us humans, inkjet printers don’t operate too well when they get over cold or hot. In low temperatures, inks thicken and this can lead to jetting issues and smaller drops being ejected by the print head which in turn will affect color. At elevated temperatures, inks will get thinner which will also lead to jetting and color problems, and print heads will dry out quicker which will cause those dreaded nozzle clogs. So, locate your printer in an area where temperature is maintained within normal indoor conditions (55 – 80 F). Avoid places in the room where there may be extreme temperature fluctuations, for instance, above heating radiators or registers; near direct sunlight or cold, drafty windows in the winter. It is important that the temperature is controlled even when the printer is not being used - no point having your machine in a nice air conditioned room during the week and then turning the air con off over the weekend, unless you enjoy spending Monday morning running loads of head cleaning cycles! Inkjet printers also hate low humidity so, if you live in a hot and arid region then consider using a humidifier in the room.
2.Always store your inks in a temperature controlled environment. Keep your spare cartridges or inks in the same temperature controlled location as your printer if you want to avoid the same print issues mentioned above. If replacement inks have been shipped to you in the middle of summer or winter where they may have got excessively hot or cold during transit, then let them adjust to room temperature for a few hours before installing them. I once talked to a gentleman who stored all his spare cartridges in his refrigerator; his logic being that this would increase their shelf life. While there may be some merit to this idea (although I am not aware of any technical reason) the problem with this approach is that you would need to let a cartridge stabilize to room temperature for a few hours before using it – not that practical when you are in the middle of a print job and a color runs out.
3.Always store your media in a dry and temperature controlled environment. Inkjet media for aqueous ink printers is coated with an ink receptive coating that is designed to rapidly absorb water, so they naturally absorb humidity from the environment. It is therefore important that you store your print media in a dry and temperature controlled place, ideally in the same room as your printer. The humidity and temperature level of a media can affect the color of a print, For instance, a media that has been stored in a cool high humidity place will not absorb the ink as quickly which affects dot spread which in turn affects color. On the other hand, a media that has been stocked in a hot dry place will absorb the ink quicker which will also affect color. It is also a good idea to let a new delivery of media ‘acclimatize’ in your print room for a day or two before use, particularly if it was shipped in the middle of summer or winter where it was exposed to extremes of heat or cold or humidity during transit. A good example of how temperature and humidity can cause printing issues was with a customer I recently spoke to in the Pacific Northwest. They were printing on a clear film and had recently started to experience bleeding around the edges of black print on their images. It was the start of winter at the time so I asked where they were storing their rolls of film. It turned out they were stocking the film in a warehouse that was pretty cold and damp. After moving their film stock to their print room and letting it warm up and dry out for a couple of days, the print issue went away.
If you follow these simple guidelines then you will experience consistency in your printed output. As all good cooks know, repeating a successful recipe requires the same ingredients, quantities, and temperature. The same goes for inkjet printing (and brownies!).
P.S. Happy to share the famous brownie recipe. Just contact us through our contact form and I will e-mail it to you.
Tony Martin – Ink2image
All prices are in USD.