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Bob, First, I want to thank you for both saving Robert Krawitz's post and for pointing it out to me. Second, it does seem to refute what I said with some good arguments; I guess part of the reason why I was not aware of the post or its points would have been that it tends to be a little too technical for me to easily comprehend in detail (not being an engineer)which may have resulted in my either glossing over it or not reading it in a way that the information stuck in my mind. This is not meant as an excuse merely a statement of my limitations and proclivities. :-( The one point he makes sort of confuses me: "Download one of the manuals for a newer printer (the older manuals aren't very good, since they were playing things closer to the chest)...." I tried to check the link but the web site is one for developers which caused me to think that I would not understand anything on it - being a non-engineer and non-computer scientist. What confuses me is that I would have thought that "manuals that played things closer to the chest" would be more conservative and accurrate in their statements and specifications and, hence, better than those which "played things farther from the cheast and a little looser." If this is the case, than I would think the manuals for the older printers would be more accurrate and informative and therefore better. Other than that, I am willing to accept what he has said that I understand. :-) -----Original Message----- From: firstname.lastname@example.org [mailto:email@example.com]On Behalf Of Bob Frost Sent: Tuesday, June 04, 2002 3:18 PM To: firstname.lastname@example.org Subject: Re: Lexmark Z65 4800 DPI printer Laurie, It seems you do have it wrong for Epsons; Robert Krawitz answered this point a while ago. I have copied his answer below:- I don't care what the Epson product manager said, the Stylus Photo 1280 can print with a resolution of 2880 dots horizontally and 720 vertically. It's a lot easier to position the head precisely than it is to position the paper precisely. Download one of the manuals for a newer printer (the older manuals aren't very good, since they were playing things closer to the chest) from http://www.epsondevelopers.com/isv/downloadList.jsp. The 1280 (which I use as an example because everyone here knows what it is) can be looked at as having a printing resolution of 360, 720, or 2880 DPI horizontally: 1/360" is the minimum spacing between dots if the printer is set to use variable-size dots (dot size setting of 0x10, 0x11, or 0x12) 1/720" DPI is the minimum spacing between dots if the printer is set to use single-size dots (dot size setting of 0, 1, 2, 3, or 4) 1/2880" is the smallest addressable positioning of the print head. So you need 8 passes of the print head to print every addressable dot on a line. This isn't purely a semantic issue; it is important to know what you're referring to. "Droplet offset" is probably the best way to describe this. You can set the line to start at horizontal positions of 0, 1/2880, 2/2880, etc. and then lay dots down at 0, 8/2880, 16/2880 or 1/2880, 9/2880, 17/2880, etc. You wouldn't actually do it in that sequence (the banding would be disastrous), but that is about what it amounts to. So OK, "droplet offset" and "motor stepping" are reasonable, if vague, ways of describing what's going on. However, variable drop sizes don't actually change the grid (2880x720) of printable dots. If you're printing line art or text, having the ability to print dots of 3 different sizes on the same page doesn't actually get you anywhere; you'll either be printing nothing or the largest dot used at that resolution. What it does enable you to do is print more, smaller dots at intermediate resolutions (particularly 720x360, 720 and 1440x720; 360 DPI is intended for fast output and 2880x720 can fill the page with the smallest dots), which produces a smoother texture. How do you use variable dots? Say you're printing at 720 DPI, and you choose the medium range of dot sizes, which are something like 6, 12, and 24 pl (I'm not certain exactly what they are, but that roughly matches what we've determined for at least some printers). By experimentation, it typically takes about 11 pl dots to completely fill the page with glossy paper. We could simply use 12 or 24 (to be safe) pl dots (which is what we do on the Stylus Photo EX, which only offers single dot sizes, albeit in about 4 different sizes). However, the results will be less smooth than if we use 6 pl dots in pale areas. If we're printing at 2880x720, we'll use the smallest set of variable dots, which is something like 4, 6, and 12 pl. However, we don't actually need larger dots at this resolution; there are so many dot positions that even 3 pl drops will solidly fill the page. However, the 1280 doesn't offer a single drop size that small; we have to use the variable dot size (which means that the output is twice as large, and it takes twice as many passes to print), but in practice we only use the smallest drop size. So maybe it's semantics (remember that I'm a driver developer, so perhaps I look at things a bit differently), but I don't think of variable drop size as actually changing the resolution available from the printer. High resolutions enable you to use very small dots, for improved quality, and the way Epson printers are set up you have to use variable drop sizes to get the small dots (the smallest *single* dot size I'm aware of is about 10 pl, on the Stylus Photo 700, EX, and the Stylus Color 800 and 850). Admittedly there would be little point in using 10 pl dots to print at 2880x720. -- Robert Krawitz <email@example.com> http://www.tiac.net/users/rlk/ - Turn off HTML mail features. Keep quoted material short. Use accurate subject lines. http://www.leben.com/lists for list instructions. - Turn off HTML mail features. Keep quoted material short. Use accurate subject lines. http://www.leben.com/lists for list instructions.