Optimizing .pdf Imagery
To optimize the .pdf imagery on your web site, you should be aware of a number of techniques that you can use in effort to reduce the size of those files:
- When using imagery, try to use vector imagery instead of bitmap whenever possible.
Vector graphics (.ai, .cdr, .svg, etc.) are typically smaller in file size than their bitmap counterparts (.jpg, .gif, .png, .tif), and will generally lead to smaller overall .pdf output.
- Pre-size your bitmap images to the dimensions you wish to display in your .pdf file.
Since information on literally every pixel will need to be stored as a part of any bitmap image you are embedding into your output, the fewer the pixels you require to be described/stored, the smaller the resulting file size will become. Consequently, make sure to size your imagery to the exact dimensions you are wanting to have them appear on a .pdf file's page, no more, no less.
- Remove any excess colors.
Using grayscale or black and white graphics in your .pdf files can cut the size of the resulting output by more than half. However, if you will require the use of color graphics in your .pdf output, strongly consider the use of RGB color over CMYK, as RGB has one less data channel to store, which will subsequently result in smaller file output size.
- Reduce the total number of fonts embedded within your .pdf document.
Each font that is embedded into your .pdf output can significantly add to that file's final output size...as much as 30-50 KB. The use of subsetted fonts within a .pdf document can help reduce overall file size as well, although you will achieve the best results by using the fewest number of fonts within the document as is possible.
- Disable all thumbnails and other "editability" functionality.
If your .pdf document is more informational in nature and is not meant to be interactive (such as a form that an individual would complete and return to you), disabling all editing functions when generating your .pdf output will make the resulting file as light-weight as is possible. This is why .pdf files which do not have editability for Adobe Illustrator (.ai) preserved are often much smaller in size. Thumbnail previews of .pdf files are often unnecessary as well, and disabling this feature can reduce the overall size of the files you create.
- Experiment with different methods for generating .pdf output.
Printing output to .pdf format will often result in a smaller file size than exporting to .pdf format, particularly when using Corel products and/or creating output from Adobe Illustrator. Other third-party .pdf output generators can often achieve superior compression results than Adobe products such as Acrobat, Illustrator and Photoshop as well. Experimenting with different methods for generating .pdf output can often lead to substantial savings in file size.
Tools that will allow you to complete these techniques:
Adobe Acrobat (Mac/Windows): Cost: $$$$ | Quality: A | Ease of Use: B | Use With: 1, 2, 3, 4, 5, 6
PDF995 (Windows): Cost: Free/$ | Quality: B+ | Ease of Use: A- | Use With: 6