Member
CD9 both updates, when I choose color seps the Always Overprint Black is greyed out. I have very close registration for t-shirt and printer has problems with this. Background is black and I need the knockouts so printing diff levels won't work with this one. Any suggestions?
Marie
Member
CD9 both updates, when I choose color seps the Always Overprint Black is greyed out. I have very close registration for t-shirt and printer has problems with this. Background is black and I need the knockouts so printing diff levels won't work with this one. Any suggestions?
Marie
Member
The feature you're trying to use is only available when printing to PostScript printers (as is overprinting on the color level). However, you can still cause overprinting at the object level. (Right-click on the object and select "Overprint Fill" or "Overprint Outline.") Of course, this can take a long time on a complex document.
Or, you can provide a color-separated PostScript print file for outputting at your screen printer or elsewhere. Select "Device Independent PostScript File" from the list of printers and the "Always overprint black" button will be available.
Member
Thank you Ziggy,
The printer needs hard copy so I'll try your suggestions. Fortunately the HP4500 has ps driver included so I'll try that too.
why didn't the 'help' topic tell me it was for ps printers only??? Bummer
But I forgot one other problem. I need to print out the file in 300 or less dpi for the t-shirts. I can do this with HP4 Driver PS? But when I download drvers from hp's site they never seem to install properly anymore. Can't get lower resolutions to print even though I can select 300 or less dpi.
Marie
[This message was edited by inphoenix on October 08, 2000 at 01:32 PM.]
Member
I think you and/or your screen printer are confusing two different terms.
One is the "resolution" at which you print your art. There is only one reason to print at anything less than the highest resolution, and that is to increase the speed at which your laser printer outputs a page. Obviously, this is not an issue here and so you should print at the highest resolution possible.
The other term is "screen frequency," which must be matched to the printing surface, and which is only variable on PostScript printers. For instance, National Geographic magazine is printed at 150 lines per inch on highly coated paper. The sunday morning comics are printed at 85 lines per inch on newsprint. Tee shirts are usually printed at 60 lines per inch on cloth. The frequency goes down as the surface becomes more coarse and therefore more likely to absorb and blur adjacent blobs of ink.
If you DO have a PostScript printer, this latter perameter is controlled globally at File/ Print/ PostScript/ Screen Frequency, and can also be controlled per color and per object (but only on PostScript printers).
Member
Ziggy,
Yes I need to print at the lowest resolution possible for the t-shirt screen printer on hard copy. I've contacted HP and got a 'run around' and finally someone who will research less than 300 DPI printing. I am trying to figure out how to change one object in a color separation printout to the lowest possible (60 dpi) as it is a 40% black and need low resolution. If you can help me with steps to take to accomplish this I would appreciate it. I've selected the object and gone to help re: lpi and am looking at help on 'halftones' that's as far as I've gotten.
20 minutes later - I tried the lpi thingy and took it down to the minimum and still prints out in 600 dpi. I'm so frustrated at this whole mess. HP as much as told me I should not be using a $3000 printer to do such low resolution "Driving a Ferrari to do grocercy shopping" I say the Ferrari should be able to go to the grocery store for what I paid for it!!! So do I have to go out and buy some low resolution post script printer? If so I'll do it if I knew what to buy.
Marie
[This message was edited by inphoenix on October 16, 2000 at 04:01 PM.]
Member
Please look at your last post: You say, "I tried the lpi thingy and took it down to the minimum and still prints out in 600 dpi." In other words, you adjusted the lpi and you're upset that the dpi didn't change. Why should it? It's as if you changed the idle speed on the engine of your mythical Ferrari and are shocked that the number of tires stayed the same!
The core of your confusion lies in the unfortunate fact that discussions of lpi often use the word "dot" to describe those 60 dark blobs in each inch at 60 lpi. (I just checked in the PhotoPaint 9 manual, and they do it in there.)
In a graphic design class, those blobs are not called dots. They're called "half tone cells" and they are very different from the microscopic dots involved in the "dots per inch" measurement. A half tone cell is actually a REGION visable under a loupe in which a cetain number of microscopic dpi-type dots live.
For instance, on a printer printing at 600 dpi and 85 lpi, there will be 600/85=7 dpi-type dots living in each cell horizontally and 7 vertically for a total of 7x7=49 dpi-type dots in the entire cell.
When you look at the array of blobs in a half-tone image, you are actually looking at an array of these cells. A large blob means a large number of microscopic dots are turned on in that cell. (For 50% black in the example above, about 25 of the 49 microscopic dots would be turned on.) A small blob means a small number of microscopic dots are turned on. If no microscopic dots at all are turned on, the cell is white. If all the microscopic dots are turned on in a cell, then that cell is pure black.
Are you beginning to understand? You know that a halftone consists of little spots. But you apparently did NOT know that those spots are THEMSELVES composed of even tinier spots! "Lines per inch" specifies the larger spots, while "dots per inch" specifies the much smaller spots inside them.
Notice how incredibly confusing this whole issue becomes if one starts to use the word "dot" to indicate BOTH the microscopic dpi-type dots and ALSO the much larger half tone cells. It is for this reason that you are confusing dpi (a measure of tiny microscopic dots of which you, Marie, shold always want as many as you can possibly get) and lpi (a measure of the much larger half tone cells of which you want only 60 in each inch on a typical tee shirt, but you want 133 if printing on glossy card stock).
Marie, I have invested quite a bit of time in trying to explain this because this is a very widespread misunderstanding. You are certainly not the only person (or the only visitor to this forum) who suffers from the sort of incredibly unprofessional drivel contained in such documents as Corel's PhotoPaint 9 User Manual.
Indeed, you are to be commended for keeping your cool as well as you have done.
Now, please, so that I won't feel that I've wasted my time, write back and tell me that you understand that lpi and dpi measure two different things, so that it is quite possible for a printed document to have BOTH 1200 dpi AND 60 lpi.
Your screen printer needs you to accomplish 60 lpi, not 60 dpi. I will be happy to help you accomplish 60 lpi, but you will never accomplish 60 dpi and there is no reason why you would want to. It would be like trying to drive on three wheels.
[This message was edited by Ziggy on October 16, 2000 at 08:05 PM.]
Member
I plan on printing that out for use in my Graphics for tech writers class. It is one of the best and clearest explainations I have ever seen.
Now I know why you are a moderator and I'm an observer.
Pat Gibson
New Member (No PMs)
You may be in the same boat as I, not all 'post script' printers are capable of changing the LPI. I have an Epson 3000-CPS and have access to all the settings in the print menu to change halftones but still nothing changes on output. I contacted Epson and asked why my injet post script printer could not change LPI and got a royal run-around, they told me I shouldn't be trying to change LPI on a desktop printer and that I needed an image setter to do what I wanted. Funny, my old desktop 300 dpi laser (until it died) would change LPI from 1 to 90. We occasionally need to print seps for T-shirt screen printers so I've learned to fill objects with 'post script' fills that will work within 40 to 55 LPI for the correct dot size for their screens. Lots of trial and error but it can be done. Still waiting on an informed reply from Epson, thanks Ziggy for the in-depth explaination on DPI/LPI.
Larry Elliott.....
Member
Pat... Thank you for the flattery but what I offered up above is merely some of the stuff that a person must know to get a degree in graphic design.
Incidentally, I just checked the manuals for Illustrator, FreeHand, PageMaker, Quark and PhotoShop and believe it or not every one of them uses the term "dot" for both dpi and lpi! Only PhotoShop even mentions halftone cells, and only in the very confusing definition, "Screen frequency: the number of printer dots or halftone cells per inch..." By using the word "dot" in that way, Adobe has succeeded in confusing every novice that reads the manual.
Elliott... Since PostScript fills are another feature unavailable on non-PostScript printers, the fact that you're able to do the one but not the other implies an incorrect setting somewhere. If you like, you could list for me all the settings you're changing and also all the pertinent settings you're leaving alone and I could try analyzing that information.
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