offset printing question

What the printer will need is a high resolution file to make seperations from. There is a screening process involved if your artwork contains any halftones, but if it is just line art and is high enough resolution than a tif would work fine. If it's line art make it 600 dpi. If your artwork contains halftones (gradients, continuous tones) than make sure the resolution is 2X the lpi of what the printer accepts, otherwise the pixels will render as halftones around the edges and your business cards will look crappy on the edges.

Offset uses printing plates, which take a while to set up. Unless you are ordering a lot of business cards the printer will try to combine your order with others and impose a number of cards on the one plate. If that is the case he can just place your tif into indesign or quark, screen the image, make seps, and burn your images onto the plate with a platesetter. Some old people still use film and filmsetters but the industry is quickly moving away from that.

If it's a 72 dpi image that was pulled off the web or something, then there is absolutely no way that it will work for offset. The quality of offset is too high and web images are too compressed. You can't print things pulled off the web and expect them to look decent.

What any printer prefers is a nice vector based image that is not resolution dependent (points, lines, curves) such as an illustrator file. Processes such as waterless offset have capabilities to print 300 lpi screens, which means your resolution requirement would have to be 600 dpi at actual size. With traditional offset you can get away with a 300 dpi image and still have it look ok because 133 lpi is SWOP (standard for web offset printing) standard. If you are creating your image in photoshop than go to image/image size and check the size of your file. 600 dots per inch is overkill for most offset capabilities, but in case you are getting it printed at some high-tech waterless printer your artwork would work. Best to make it higher just in case and reduce the size right before giving it to the printer. Most printers use a 133 screening so if it's 300 it'll work.

Vector artwork is always best, however, because you don't have to worry about silly things like resolution. Just make sure you make it actual size and it's "camera ready" artwork. Mark up what colors you want, the sizes, bleeds, and all that. With offset they have to make a plate for each color so if you are doing a full color image than you will need 4 plates. If it's only a 2 color image than they will only have to make 2 plates.

Talk to your printer about what processes they use.

-ko

How high-end is your business card? If it's just the standard black-and-white variety, you could probably get away with using Photoshop (at a high enough resolution) printing it on your inkjet and submitting that as 'camera-copy' for your printer. For an embossed card, 300 DPI or so would work fine.

If you're looking for a fancier card, then it really depends on what you're planning to do with it. I've seen some very nice business cards for photographers, where really the card is a sample of their work. Photoshop might actually be the best option for that kind of card.

meta-ghost said:

i know photoshop files are not exactly what you use for offset printing but can anyone tell me if it's possible to take a tiff image from photoshop and print requesting offset printing? it happens to be a business card and i don't have illustrator, quark or any of the proper software.

Click to expand...

In a nutshell, Photoshop files are exactly what is used for offset printing. Having been in commercial printing for over 30 years and almost 20 of that in desktop publishing (Scitex 1982).
First of all lets clarify what programs do what. You say you don't have Illustrator or Quark, those are two completely different type of apps.
1. Page Layout Programs, QuarkXpress, PageMaker, InDesign, Publisher
2. Image editing (bitmapped) Programs, Photoshop, Painter, and probably more I am not mentioning here.
3. Drawing programs (vector art) Illustrator, Freehand, Corel Draw etc.

As rfenik stated there are rules of thumb to remember about resolution. lpi refers to lines per inch which is the way halftones and gradations are printed in offset. the most common of these is 150lpi magazines such as National Geographic will print up to 300lpi which can produce extremely clear and detailed photos. Your Sunday comics (printed on a web press) will usually run 85-110lpi. So the resolution (dpi or ppi)of your photo should be based on the finished size of the image to print i.e. to print a halftone at 100% of original size at 150lpi the resolution should be 300dpi. This is based on a mathematical formula on how the RIP (raster image processor) interprets the information of the image based on 256 steps of gray. (it would take a few more pages to explain fully). Line art or simple black&white should be based on the final output device. Since most modern day imagesetters and platesetters RIP at 2400dpi and higher your art should be scanned at the highest possible resolution as will be output.

Vector art on the other hand, is based on mathematical formulas (usually postscript language) and has no bearing on the original or final output resolution, since vector art has no resolution, dpi or lpi doesn't apply.

Photoshop is a wonderful program (the best in my opinion) for editing, and creating custom pictures and halftones, and the accepted standard of file is either .TIFF (tagged image file format) .eps (encapsulated postscript) for commercial printing. File formats such as .JPEG use compression to reduce file size and as a result every time the file is opened and saved a certain amount of information is lost and eventually will result in file degradation.

And don't forget, you'll want to work in CMYK if there is any color in the image. Although unless you are doing full 4-color press work, you'll definetly want to stick to easily obtainable PANTONE colors. For a nice but cheap card consider going with black plus one other color. If you want to get really fancy you can use a 50% and a 100% saturation? value of the color to get different effects with the same color (and dollar) at the printers.

mactastic said:

And don't forget, you'll want to work in CMYK if there is any color in the image. Although unless you are doing full 4-color press work, you'll definetly want to stick to easily obtainable PANTONE colors. For a nice but cheap card consider going with black plus one other color. If you want to get really fancy you can use a 50% and a 100% saturation? value of the color to get different effects with the same color (and dollar) at the printers.

Click to expand...

Thanks, I didn't want to get into color, although I know it's an important consideration and especially effects pricing on a job.

Simply put, RGB, L.A.B., Indexed, colors are no no for printing, CMYK, Pantone, or Hexachrome are OK.