Printing at 450 Line Screen
One of the things I enjoy about my job is talking to printers. I love looking at print and paper samples, and I love learning about the latest print technology. I love touring print shops, and I love press checks. I love the pampering that comes with being courted by printers. I think if I had a second career, I would want to run a huge press.
Well, since our company recently moved, we are exploring some of the local printing options, and that means I get to meet some new printers. Today I met with Steve Johnson from Colorado Printing. The website isn’t much to look at (holy animated gif, Batman!), but the quality of their printing is. Specifically, they are able to print at 450 line screen on a sheet-fed press. I was expecting him to say they were using stochastic printing, but to my surprise, he said their high line screen is created with a square dot. Very interesting.
The photo reproduction Steve showed me was so beautiful that the thought of continuing to use a 130 line screen web press doesn’t excite me, to say the least. I instantly notice halftones in most 4 color printing, and I hate it. I think it is because of my photography background, because when I see a coarse screen the voice in my head says “cheap, low quality.” Not a fun phrase to be bouncing between the ears, especially when you put so much time, effort, and money into the design and photography of a piece. In a twisted bright side to the situation, I think that most people barely notice a difference between 150 and 450 linescreen. To my dismay, that makes a high line screen a hard sell, and I am probably fighting a losing battle if I want the high quality. However, if you have the luxury of selecting a high quality printer, I suggest you give Colorado Printers a call. In addition to 450 line screen, they also have some impressive new proofing systems. And like any printer, I am sure they would love to tell you all about it.
February 18th, 2005 at 2:13 pm
Adrian, gotta say I share your love of being around the presses. Its kind of a rush to see entire forests rage past your eye in microscopic slices!
Are they using UV ink and drying between inks? It seems many printers are revisiting this area. I believe Colorado Printing may be using the same process or a variation of what one Seattle press uses. Check out Olympic Press Hi-Definition On Press process. I think a lot of printers are re-branding a technology that is based on stochastic printing.
I used Olympic for several projects and it was interesting to see the different challenges faced by this printing. I had some new issues with banding and edges being found in light gradations, because the process can pick up such finite particles and put ink downÓàΩt was a much bigger challenge than with traditional screens. The process also seemed to have greater color shifts. But it also resulted in much more vibrant colors. And it seemed that color matching to process versions of Pantone colors was difficult. The CMYK percentages of colors didn’t always match up to those recommended in the Pantone books. However, the color range seemed much betterÓâ£nce you found the right percentages, you could get closer to actual spot Pantone chips than you could using traditional screens. However, it seemed to be not as successful on uncoated papers. I would prefer to print 200 linescreen on a UV press than use the “HDOP” process on most uncoated papers. It would be interesting to see “HDOP” on a UV press to see if it improved uncoated printing.
February 18th, 2005 at 3:08 pm
450 line screen just sounds ridiculous to me. Isn’t CA printed at 200 line screen. I think the printing of CA looks pretty amazing as it is. Is 450 even detectable to the human eye? Wouldn’t 250 be about all that we need for incredible looking print pieces?
What are you supposed to do as far as dpi? Are you supposed to have a higher dpi than line screen as you usually do, or does this not apply to this type of printing. Do we have to start sending in files at 600 dpi?
February 18th, 2005 at 3:55 pm
My experience was that 400 dpi was the target. I did send some out at around 300 dpi and they were fine as well. I think the dot pattern actually might be more forgiving than that, but I’m not sure. If you think of inkjet printers, they can print substantially lower resolution than traditional screens…and I believe it is because of their dot pattern…which might be more similar to a hi definition screen than a traditional screen…just a guess. I’ll e-mail Olympic Press.
February 18th, 2005 at 4:39 pm
It looks to me like Olympic Press and Colorado Printing both use the same press, a Heidelberg Speedmaster 10, but I don’t remember him saying anything about UV ink or drying between inks. He did say that the ink they use has more varnish in it. Several printers I have used have done a flood varnish to protect the ink. With the better ink, you don’t have to do that.
From the samples I look at, halftones disappear to my eye at 250 lpi. Above that, the visible improvements would be better color. With 450 lpi, Colorado Printing has there own pantone to process conversion chart. At that high of lpi, it takes a little different CMYK build to match pantones. That’s the way I understand it, anyway…
February 18th, 2005 at 7:07 pm
Actually it is another printer (Colorgraphics) that has the UV press. Here is an *American Printer* article about their UV press.
They use the UV to negate dot gain. It is very helpful on uncoated, foils, plastics, etc..
February 19th, 2005 at 1:26 pm
just got an e-mail from Glenn Blue at Olympic and he said 400 is ideal, and that he has printed files as low as 200 dpi, but that is a real stretch…probably kind of a waste to be printing hi-def if your files are 200dpi.
February 21st, 2005 at 3:09 am
I sure would like to see samples of 450lpi. Using square dots is interesting. Would square dots improve offset printing on 150 or 133 lpi which is the standard in my place.
February 21st, 2005 at 3:40 pm
Jimmy, I’m far from an expert in this area, but I do not believe that square dots will work in a traditional 150 lpi. I believe they require a “random” pattern rather than the equidistant line-screen in 150 lpi. It appears more like an inkjet print in that the dots are scattered and make no discernable pattern.
February 21st, 2005 at 4:24 pm
I don’t know for sure if the square dot has a random pattern or not. I didn’t think it did, but I could be wrong. I invited Steve Johnson from Colorodo Printing to our site. Maybe he can clarify.
March 1st, 2005 at 7:57 pm
If a printer is referring to ‘linescreen’ that means they are using an amplitude modulated dot that is set in a line or regular pattern. The position of the dots is constant while its diameter changes to create different values. A ‘random’ pattern only exists in stochastic printing (which is what most inkjets use) or ‘frequency modulated’ printing. In this method the dot size is constant while its position and proximity to other dots create different values. There is no linescreen in this method. With a linescreen at 450 lpi the largest dot is considerably smaller than that of 150 lpi and so it is more difficult to see the dots, no matter what shape they are. I am curious about the dot gain on such a fine line screen. From my knowledge, we can make plates with much higher resolutions and line screens, but the viscosity of the inks and the press’s ability to control the amounts of ink are the limitations. Remember that the resolutions of presses, or more specifically the film and platemakers, is something in the area of 1200 to 2400 (I’m not a pressman, so I could be wrong) but regardless, greater and greater precision of linescreen is not a mountain of image quality without a peak. I’m sure Adrian and Bennett can uproot what I’m saying in a second, but from what I have read and seen, this is how it works and I thought you all might benefit from hearing it. Or you could be a whole lot dumber.
March 1st, 2005 at 9:30 pm
Simanek! Thanks for your insights. Everything you said sounds right to me.
I keep pushing for the high quality printing, but it isn’t going that well. It seems to be a continual game of the “Emperor’s New Clothes.” First, I am not sure if my boss will be able to tell the difference. My boss isn’t sure if our client will be able to see the difference. The client isn’t sure if their customers will notice the difference. Sigh…
March 3rd, 2005 at 3:34 pm
When it comes to high definition screening technologies, the most important thing to keep in mind is the intended use. Adrian, as you have pointed out, will the client’s customers notice the difference? For instance, on a high-end marketing piece, the customer might not ‘notice’ how it is printed, but they will notice that the colours are vibrant, and the images jump off the page.
For this reason, our company (a printing company in Vancouver, Canada) regularly uses either an advanced 300lpi screening technology (AM screening) OR 20 micron stochastic (FM screening), depending on the intended use, and the images in the job.
As Clinton pointed out, the downside of FM is “microbanding” or as he called it, “banding and edges being found in light gradations”. This is not the fault of the printer, it is inherent to stochastic screening. If your job has flat tints, or subtle graduated screens, AM is the better choice. The downside is that FM has in the past been the only way to get more vibrant colour. But now, printers are pushing the envelope, (and in our case, employing new screening algorithms) to increase the lpi of what was once called ‘conventional screening’. This sounds like what Colorado Printing is doing.
Most of all, remember that once you’re above about 250-300 lpi, (or 20 micron if you’re going stochastic) the dot becomes invisible to the casual observer. So 300 or even 400 is about as high as you would need to go to get those amazing eye-popping colours.
March 6th, 2005 at 2:29 pm
Ken, thanks for sharing your expertise!
March 8th, 2005 at 12:16 pm
Yeah, thanks Ken!
September 23rd, 2005 at 9:48 am
The following is more venting than anything else: After lobbying for the best printer possible, the decision was made mainly on price. We gambled that the client wouldn’t be able to tell the difference, and we lost. The color was off to the point where one half of a spread didn’t match the other. While I should feel a little validation in my efforts to push for higher quality, instead I feel like the blame is getting directed at me! I just can’t win sometimes…
April 10th, 2009 at 4:07 am
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