Hi, I was wondering if someone out there could help. I've just recieved specs for a job and one of the essentials is Understanding of print production process in the utilisation of digitised photographic images. could anyone please offer any advice or help in the settings ie unsharp mask, resolution etc required by printers, also with regard to scanning images what's the best way of doing this, at the moment I only print at 300dpi and so I scan at 300dpi, is this suitable for the print industry. I realise different printers would have different requirements so any general advice would be greatfully recived. cheers Drag0n98

300 dpi is the standard res for print. The best advice is to scan as high(if you want high quality) as you can and then reduce the resolution and size in photoshop. Check with the printer or client what format they want the final image in(.eps,.jpg etc). Generally the image on your screen will look like the prited image - if your monitor is old or not calibrated properly(Use the Adobe Gamma soft' that comes with P'Shop) then try to look at the image on different monitors. If you are printing to a paper(as opposed a magazine), always tell the printer to 'knock back for press', this is because presses actually roll out the ink with a series of dots and any image will appear slightly darker. In a push you can do this in photoshop by applying a 15% white layer on top, but it's always best to let the printers do this.

Dealing with "digital" images is often a little different than traditional "photographic" images. Often there is more color correction needed.

As for the UNSHARP MASK its name is a bit misleading (you might think it would "blur" the object). It is a holdover from the old darkroom days, and actually sharpens the look of the image.

The "amount" slider determines how much to increase the contrast of pixels. For high-res printed images, something between 150% and 200% is a good setting.

The "radius" slider determines the number of pixels surrounding the edge pixels that affect the sharpening. For high-res, a setting between 1 and 2 is usually good (a lower value sharpens only the edge pixels).

The "threshold" slider determines how different the sharpened pixels must be from the surrounding area before they are considered edge pixels and sharpened by the filter. Experiment with values between 2 and 20 (default value 0 sharpens all pixels in the image). Another good "sharpening" technique to use is the Lightness channel of LAB mode (if interested i'll explain later).

As for resolution, the quality of your piece will depend not only on resolution of your scan, but also on the resolution of your output device (printer) AND the size of the original image as it compares to the final image output.
(This is often an issue when needing to scan from slides)

NOW FOR SOME MATH:
Multiply the screen frequency by 2 (the typical ratio of image resolution to screen frequency needed to produce a high-quality image - check with your printer...).

Then multiply the result by the ratio of final image dimensions to original dimensions to determine an estimated scan resolution.

Say you have a 1 X 1-1/2 slide that you need to scan and you need to ouput it to a 6 X 9 with a screen frequency of 133lpi (lines per inch). Multiply 133(lpi - the screen frequency) by 2 to get 266. Then multiply 266 by 6 (this is the ratio of final output dimensions to original slides dimension) to get a scan resolution of 1596ppi (ppi - points per inch). Check with your print specs in regard to the screen frequency needed...

Hope this helps,
:)
retrocity

As for more on color correction, please remember one important thing that 80% of designers (and salespeople) always forget: Unless you and your service bureau have the exact same make and model monitor with the exact same calibration settings, the colors are not going to be the same. With that said, apply that same theory to printing presses. I work exclusively with a printer who has 3 digital wide-format presses and each one prints differently even though they're the exact same model, etc. Also, the resolution (as Retrocity covered quite well) is very important! I design mostly billboards and large-format prints so everything we do is 400dpi, but there's nothing that irks me more than a client sending in a 3"x 5" 72 dpi photo or artwork. It drives me nuts how people don't understand relative resolution. Ok, before I start to sound too bitter :) I just wanted to add all that in. Good luck!

Thanks for the info. Retrocity I'd be greatful if you'd tell me about using the lightness channel of LAB mode again my thanks for the posts Drag0n98

DragOn98, this method isn't for every type of image, in fact if the image is going to be used on the web, this only adds steps to the process and doesn't really add any benefit. But if you need to retain color as well as sharpen the image try this: Open your image (RGB, CMYK) and convert it to LAB color (Image --> Mode --> Lab Color) In the Channels palette, click on the "Lightness" channel to make it the active one. You'll notice it deselects the other channels. Click on the "visibility" icon (eye) next to the "Lab" channel to make all the channels visible. Open the unsharpen filter dialog box (Filters --> Sharpen --> Unsharp Mask) Since only the "Lightness" channel is active, any adjustment or modification will affect this channel only. A couple of notes at this time: You will be setting the values higher than normal, you can increase the "amount" value by 25-50% and 75-100% higher value in the "radius" slider than you would apply to the image in RGB mode ("threshold" should stay the same). Another thing, a good rule of thumb is "threshold" set to 1 with "radius" set to 2 is better than "threshold" set to 0 and "radius" set to 1. Make your adjustments as needed (for example: "amount" = 100%, "radius" = 1.7 pixels, and "threshold" = 1) When you feel satisfied with correction, convert back to the original color mode (RGB, CMYK) and make anyother modifications to the image. It's probably a good idea to look into more info regarding LAB color mode and how this mode looks at color differently in Photoshop. Hope this helps, :) retrocity

Attached Link: http://www.renderosity.com/softgood.ez?ViewSoftgood=11528

If any of you are going to the Renderosity/Dragon*con Convention, Jeff Flower is giving an outstanding workshop on just this subject. Well worth the trip if only for taking this class. More information can be found at the above URL ladynimue

Lady, thanks for the link. Looks like a very informative workshop. The syllabus covers a great deal of important topics, looks to be well worth going to! :) retrocity

Ok... For one thing. ALWAYS Use HIGH RES PICTURES!!!!!!!!! Gawd, nothing is more aweful than someone sending a picture that is 72 dpi, I just hate it. When you scan pictures, use a real high resolution. Here is a tip.... Making things smaller make them look better, as in a picture that is 300 dpi and 20" by 20" will look really well when you bring it down to say 10" by 10". BUT if the picture is 72 dpi and 5" by 5", it will look awfull when you bring it up to 300 dpi 10" by 10". Also, the standard for printing is CMYK color and 300 dpi. Atleast, thats what i've been led to believe. Really, you learn this stuff as you gain experience doing it. You'll figure out what works best, etc, etc... The real key, or whatever you want to call it is to always use hi res pitures. It makes life so much easier, and makes the end product look a lot better. Oh and the bigger the image is the better... Hi res is good, but a hi res 20" by 20" picture is better than say a hi res 1" by 1"... Atleast, thats what i've come to learn. I'm still somewhat new to the whole thing though, just turned 17. I have 5 magazine ads published so far, and this is just what i've learned along the way... Oh and if your wondering what CMYK means... It's Cyan Magenta Yellow Black, I think thats how printers print. With those colors I mean... Pretty sure... So I always try to work in CMYK mode instead of RGB mode when doing print work. If I can do it though, no worries, anyone can.

Oh and some printers want the file saved differently... I've had to save it as EPS, Tiff, and even JPG... So always ask how the printer wants it...

One other thing... If you plan on using filters a lot, then you'd be best to work in RGB, some of the filters won't work in CMYK... I don't us filters much so I forgot, sorry.