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general | graphics | color | layout | fonts
GENERAL
· Check the general preflighting section of this guide.
· Print separations to check that your job will color separate correctly.
· Make sure your file works before sending it to us. If you are having problems with it (i.e. your images are not printing right), please call us before sending it in. We are more than happy to help you fix the problem spots and if we know about it ahead of time it prevents production delays.
· Web files which use compression degenerate in quality with repeated openings and closings. It's best to save them as TIFF files the first time you open them.
ACCEPTABLE COLOR MODES
BITMAP
· Creates 1-bit line art images wherein any given pixel is either black or white. It does not allow for greyscale effects, shading or gradients.
· These graphics must be color separated manually as the entire graphic can only be given 1 color (i.e. in a 2-color logo, items that print in color 1 are in one file and items that print in color 2 are in another file). You should place and colorize these files in your page layout document.
· Bitmap graphics will have a transparent background.
GREYSCALE
· Creates B&W graphics with various shades of gray.
· Be careful that your photos are not too dark or too light. Light areas should have 2% color and dark areas should generally be 92%.
· You can place and colorize these files in your page layout document; however, if they are to be printed at a percentage of the color, you should alter the file in Photoshop (i.e. use the Curves dialogue box to screen back the image).
· Greyscale graphics will not have a transparent background unless you create a clipping path.
DUOTONE
· Creates graphics wherein the same image is printed in 2 or more different colored inks to achieve depth and artistic effects.
· Be careful of duotone curve setup. Too much saturation (especially on an uncoated sheet) can cause the image to look too muddy and unclear. Conversely, too little ink can create a washed out look. Contact us if you plan to incorporate duotones in your project.
· Be sure to specify Pantone color names in your duotone color setup.
· Duotone graphics will not have a transparent background unless you create a clipping path.
CMYK:
· This mode is used for full-color graphics such as photos. You generally cannot use this mode for printing spot color.
· Keep in mind that items set up in CMYK mode for spot printing projects need to be correctly set up using channels. If this is not a possibility, use greyscale mode to separate the individual elements and combine them in your page layout document. Call us if you would like to incorporate spot channels in your Photoshop file
· CMYK graphics will not have a transparent background unless you create a clipping path.
UNACCEPTABLE COLOR MODES
· index color
· RGB
· LAB
LAYOUT
· Set up bleeds correctly. Your image should be oversized to allow for bleed setup in your page layout program.
· While Photoshop is generally not used as a page layout program, be sure to set up margins and panels correctly. A general guideline is to make sure you put twice the amount of your outside margins between your inside columns. This is to make sure that when the brochure is folded, there will be the same amount of space between the edge of the text or graphics and the edge of the paper on all sides of the panel.
RESOLUTION/RESIZING
· Resolution refers to the number of pixels per inch contained in your file. A pixel is a square component of a raster graphic and can best be envisioned by imagining a grid superimposed over your image. The closer together the lines of the grid are, the more squares (pixels) there will be in any square inch of area. The more squares you have, the greater the detail you can achieve; however, there IS such a thing as having resolution set too high.
· The best general formula for determining print resolution is (linescreen of your output device x 2) x (percent reduction/enlargement). Generally, Lithohaus film is run at 150 - 175 lines per inch (lpi) for jobs on coated papers and 120 - 133 lpi for jobs on uncoated papers.
· To determine the extent to which you can resize your raster-based graphic, use the image size dialogue box and make sure you constrain the proportions to avoid distorted file sizing. Keeping the "Resample Image" box unchecked will allow you to see how large your file can become without sacrificing resolution.
FILE FORMATS
DCS
· Use this with spot channel files. It will produce an EPS file and a separate file for every channel used.
· You must manually set trapping in these files. Be careful not to trap your colors too excessively.
· Save as DCS 2.0 format, select "multiple file with color composite" as DCS type and DO NOT check any of the other boxes in the save as dialogue box.
· You can use either binary or ASCII encoding.
· Make sure your file has adequate resolution and uses the correct color mode.
EPS
· Use this with duotones.
· When saving your EPS, DO NOT check any of the other boxes in the save as dialogue box.
· You may choose 8-bit previews (more detailed than 1-bit but add more to a file's size) or 1-bit (smaller but less detailed). You can use either binary or ASCII encoding.
· Make sure your file has adequate resolution and uses the correct color mode.
GIF
· This format is often used for high-compression web output -- make sure your file has adequate resolution.
· You can create GIFs with transparent backgrounds for the web, but the transparency does not hold in most printing situations. Create a clipping path and re-save the image as a TIF or EPS if you need a transparent background.
· Make sure your file has adequate resolution and uses the correct color mode.
JPG
· This format is often used for high-compression web output -- make sure your file has adequate resolution.
· JPEGs do not have the option for creating web files with transparent backgrounds.
· Make sure your file has adequate resolution and uses the correct color mode.
PDF
· Make sure your file has adequate resolution and uses the correct color mode.
· See the section on preparing PDFs for more information.
PSD
· These files allow you to save with layers.
· Make sure your file has adequate resolution and uses the correct color mode.
TIF
· These files allow you to save with layers.
· Make sure your file has adequate resolution and uses the correct color mode.
CLIPPING PATHS
Raster files will not have a transparent background unless they are bitmap line art or are saved with a clipping path. If you want certain areas of your photos/graphics to have transparency, you will most likely need to make a clipping path. This is a vector-based path which defines the area to be printed; the rest of your photoshop document will remain intact, though only that which is included within the path will actually print or display in page layout applications.
Save these the resulting image as a .tif file.
To make a clipping path in photoshop automatically
1. Use the selection tools to select the area you want to define
2. In the Path palette, select 'Make Work path' on the fly-out menu.
3. Tolerance values can range from 0.5 to 10 pixels and determine how sensitive the Make Work Path command is to slight changes in the selection shape. The higher the tolerance value, the fewer the anchor points used to draw the path and the smoother the path.
4. Select "Save Path" from the fly-out menu.
5. Select "Clipping Path" from the fly-out menu, choose the path name you just created and leave the Flatness blank.
To make a clipping path in photoshop manually
1. Select "New Path" from the fly-out menu in the Path palette.
2. Use the vector pen tools to select the area you want to define, making sure to create a closed shape.
3. Select "Clipping Path" from the fly-out menu, choose the path name you just created and leave the Flatness blank.
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