Adobe Photoshop

      Raster images are created with pixels. Each pixel is assigned a specific location and color value. Enlarging these images can greatly effect quality. (Photoshop creates raster images).

  We generally produce our plates at 100 lpi / 1270 dpi. The resolution of an image needs to be at least 1.5  to 2  times the screen frequency resulting in a 150 dpi (minimum) to 200 dpi (preferred) at full size.

Note: Resolution higher than 200 dpi will not significantly improve the quality of the image, but will result in a much larger file size.

  Line art should be 600 dpi.

  Vector images are created with mathematical formulas and can be enlarged without affecting print quality. (Freehand, Illustrator and CorelDraw create vector images). 

2. Generating Separations - Grayscale, CMYK, Spot:

  In Adobe Photoshop there are basically two ways of separating color. Undercolor Removal (UCR) and Gray Component Replacement (GCR). These settings can be found in the Color Settings dialog box. The main difference in the two settings is how the black plate is affected when converting files from RGB to CMYK. We recommend that you use one of these two settings.

Grayscale Images - make sure that images that are meant to print black or grayscale are truly built as a grayscale file. On screen an image may appear to be black but if it is in CMYK mode it may take all four plates to create that color. This is called a rich black and can create two problems on our press:

1) tracking - if the ink density is too high then the image may track to other pages throughout the book when the paper touches on press

2) registration - if registration is off slightly, you may see a halo of color around the image

Go into the Color Settings dialog box, listed on the previous page, and change the black generation to GCR/ Maximum Black. Click OK. Change the color mode of your image to RGB. Then, change it back to CMYK.

By doing this, Photoshop converts the high ink density areas to a solid black instead of a build of all four plates.

Note: Make sure that you switch the Color Settings back to your original settings, listed on previous page, for all other images.

CMYK Images -  Our press uses four plates to produce full color images: Cyan, Magenta, Yellow and Black. We recommend that all color images, excluding spot colors, be CMYK rather than RGB. This will give you more control of your images and let you see a better representation on your screen.

Spot Images - Spot images can sometimes be tricky to work with. If spot color is used it is essential that you assign it as spot in the application and that the name of the spot matches exactly. For example, if you are using PMS 201 CVU, then make sure that it is named exactly the same way in all applications that are used, like Quark, Photoshop, Illustrator, etc...
If Quark has a spot named PMS 201 CVU and Photoshop has PMS 201 CVC both elements will not show up when the file is separated.