looking for a laser printer for high detail

[thejarrick]

hi, I'm trying to find a laser printer that will print very high detail - I design artwork, like fractals, and want the detail to be seen even when using a magnifying glass.
There's a wide range of laser printers to choose from and the one's in my budget range are claiming 1200x1200dpi resolutions but on investigation, it seems that dpi isn't the same as ppi.
I'm trying to find out what the thinnest line or smallest pixel one of these 1200x1200 printers can accurately print and I'm trying to put that in terms of pixels per inch (i.e. if I'm printing a 10cm x 10cm picture from photoshop - what is the highest resolution I can create that picture so that the printer will show every detail?).

 

[Michael4]

I assume you're not talking about production printing or digital presses. You want a desktop printer for your home or office, correct? Anything 10cm and is a bitmap image, 300dpi is plenty. Larger size images may require higher resolution files 400dpi or more. Also poor image quality can result in a poor print, even if the resolution is what it should be.

Keep in mind, if you're working with type, nothing will compare to the print quality of a vector. upon close examination of bitmap text you will always see slight jagged edges.

Epson makes some great printers, 4 and 6 color process that render amazing image quality at slow speeds. Prices range from $200 and up.

 

[thejarrick]

yes, it's a desktop printer for my office I need. I do most my work in illustrator so it's mostly vector based but I sometimes rasterize it in photoshop so that I can see a better representation of what the printed image might look like.

I'm trying to work out how small I can go with my artwork and what printers can handle it. It's got to be a laser printer as I'll be printing on normal paper and I've been told that a 1200x1200dpi printer will print a line as small as 0.06pt (0.00083 inch or 0.021mm). but this is a line made up of a single colour of Cyan, magenta, yellow or black. I've heard that when you blend these colours (to make green, brown or whatever) the printer has to make a bunch of dots next to each other to form the colour and so you end up with the thinnest possible line being a lot bigger. from what I read, this is known as lines per inch (lpi).

so, is it going to be the same number of lines per inch for every 1200x1200dpi colour laser printer with 4 cartriges (CMYK)? and any idea what lpi it is?

 

[Michael4]

That's a good question. I'm familiar with LPI in offset printing. When working on an offset press, LIP depicts how fine or tight the press/plate can create halftones. (usualy printing at about 80-150LPI)

If LPI applies to digital as well, I may be clueless on this issue! I have never seen LPI as a spec for digital machines. You may have to contact the manufacturer your interested in and ask them about it. If you do, fill me in, I'm eager to know myself now.

 

[thejarrick]

well, I contacted a bunch of manufacturers (epson, dell, lexmark) and asked them about it and they all said that the toner is layered on top of each other, meaning that a 1200x1200dpi laser printer can print a line 1/1200th of an inch thick in any colour.

However - all the people I talked to, I either found it very difficult to understand their accent or they were gave me the impression that they didn't really know their onions and were just guessing.

 

[Michael4]

I wouldn't be surprised if they were guessing. Its partially a graphics question and partially a print question. Perhaps another printer may find his way to this feed and have an educated answer.

I think you will find thinner lines from printing and solid CMYK value. The layered toner never falls exactly on the same location (even with production digital machines) you will find often that one color will stagger away from the others, especially after rasterizing.

Why don't you print using the AI file? or Press Quality PDF? Is the file size too large?

 

[thejarrick]

I only rasterise ai files in photoshop because I've heard that it has a better rasterising program than the ones you can find in some printers but I don't do it all the time - just if I want to check it out in detail before I print.

I came accross an interesting test that someone did on a 1200x1200 laser printer: http://www.fho-emden.de/~hoffmann/raster16052003.pdf
and like you say, he found that printing colours on top of each other caused blur or smearing or slight missalignment. He found that the minimum line width was 0.1mm (0.28pt) which is pretty thick for what I'd like so I guess I'll be hunting round for a printer with a 2400x2400 resolution, though they're pretty pricey at the moment.

 

[ekaiser]

lpi vs dpi

It all math. If you have a printer that prints 1200 dpi and 150 lpi, then on a straight line (in one direction), each line gets 1200/150 or 8 dots, which I shall call bits to ease confusion. lpi refers to how many dots there are in an inch. Dots are two dimensional, so there are 64 bits for each dot. Since each dot, in postscript, represents one of each of 256 color, there is no way to represent 256 different shades of a color on a 1200 dpi printer that prints 150 lpi. At 175 lpi, it gets even worse.

Each dot should represent 256 shades. Since there are two dimension to a dot we take the square root of 256 which give us 16. We go for 150 lpi, so 16 * 150 = 2400. Therefor it takes a 2400 dpi printer to represent all 256 shades of each color. If you print at a higher lpi or a lower resolution, you cannot represent all 16 million postscript colors on your device, you will have to dither. If you have stochastic screening, the dithering is hidden in the screening and you get a little better numbers.

Any time you dither, you, by definition, throw away detail.

Them's the hard core facts of life.

 

[plotter]

wow