I need to create a poster for a conference. Which is the best image format that I should save my image file as for highest quality printing? I am using Mathematica on Ubuntu 10.10 to generate these images.
Short version: Export to a format that supports CMYK colorspace and maintains image fidelity. In order of preference:
- Vector format: EPS with CMYK colorspace option
- Raster (bitmap) format: TIFF with CMYK colorspace option using at least 300 DPI
Explanation: There are two factors to consider for high quality printing:
- Colorspace: is the color faithfully reproduced? Detail is often lost in the conversion from the RGB colorspace commonly used by computers to the CMYK colorspace used by printers. For example, when I printed business cards with my RGB logo, the CMYK result was much darker and "washed out." The beautiful blue color turned nearly purple and the color gradient was basically lost.
- Resolution: is there detailed enough image data to prevent unwanted artifacts/jagged edges? Printers generally print at least 300 DPI. The best approach to export raster images for printing is to match the DPI of the specific printer you will use.
Ideally, you should export as a vector format in CMYK colorspace. Mathematica supports EPS export:
- The CMYK colorspace is supported.
- The EPS (vector) format should basically store the image with basically infinite resolution because the image is stored as a series of mathematical functions.
In addition to infinite resolution, the file size should stay relatively small.
However, one disadvantage of vector file formats is text in non-standard fonts is often rendered incorrectly. In this case, it may be simpler to export a raster (bitmap) image. I suggest the TIFF format:
- CMYK colorspace support.
- TIFF has an option for lossless compression.
Make sure to use at least 300 DPI. Depending on the physical size of your poster, this could require a HUGE file.
I do not recommend:
- JPEG: supports CYMK colorspace, but introduces compression artifacts. Use the lowest compression (highest quality) setting if JPEG must be used.
- PNG: Supports lossless compression, but does not support CMYK colorspace.