Arbortext IsoDraw > Data Exchange Reference > Image File Formats > PNG > Preferences for Export > Recommended Settings
  
Recommended Settings
The settings are governed by your particular needs and are therefore very flexible. Here are a few tips to help you in special cases:
An illustration is to be converted into a raster image so that it can be used in programs, which do not support a more suitable format.
Black/White Illustrations
Export your illustration as a line-art drawing. You should obtain a final resolution of approx. 300 – 400 dpi. Enter 300, for example, if the drawing is not to be scaled again later. If, however, it is to be reduced by 50%, a resolution of 150 dpi will be sufficient. The scaling factor will become an aspect to consider when deciding on the resolution.
The resolution of the output device is also important. If the target printer has a resolution of only 200 dpi, it would be wasting space to work with 300 dpi.
Check to see whether, and if so which, compressions you can use. The simplest way to tell the quality of the compression is by looking at the size of the file.
Grayscale or Color Illustrations
If you have only used grayscales in your illustration, you should export it as a grayscale image. With color illustrations, a great deal depends on the number of colors you have used. This governs the image depth. By carefully selecting the correct image depth, however, you can reduce the number of colors in a color illustration which may be currently “too good”, e.g. if you want to reduce the size of the file.
The same tips apply for the resolution and compression as for black/white images.