Most of the time, if your file contains an image, you’ll want that image to be in bitmap mode for a nice clean bite into your paper. Otherwise your image will produce a halftone, which means your image will be made up of tiny dots on the surface of your plate.
If you zoom in on your image and it is made up of tiny grey and black pixels, it’s in grayscale. We want your images all in black pixels.
You can correct this by:
- Opening your image in Photoshop and selecting Image > Mode > Grayscale.
- Select Yes if a window asks about discarding color.
- Then Select Image > Mode > Bitmap. A window will pop up looking for info – use a resolution of 600-1200 dpi and an output method of 50% threshold.
- Save your files as a tif (with LZW Compression) and send us the tif. Or insert the Tif into your Illustrator or InDesign file.
Images in higher resolution (600-1200 dpi) will give better, finer results than images in lower resolutions (72-300 dpi). If your images lose a lot of detail, you can either re-scan or adjust your levels of black. A quick explanation about the 50% threshold method. A grayscale image is made up of pixels from 1 – 100% black. When you select 50% threshold, you are telling the computer to change all pixels less than 50% black to be white and all pixels greater than 50% black to be black. So sometimes adjusting the levels of gray pixels under 50% to a little darker and over the 50% mark will keep more details in your image. We suggest experimenting with the following: Image Adjustments > Levels or Image Adjustments > Brightness and Contrast. This may give you more pleasing results in your final bitmap tif.
Posted in: File Preparation, File Preparation