A Quick Tip For Reducing Adobe Illustrator File Size
Getting Started – We Will Lay Out Some Custom Binder Artwork
In this article, we discuss using Adobe Illustrator to crop images. We will start by opening a SpeedBinder custom binder template file. In this case, a 1″ ring size, half sheet size full color vinyl binder template. It looks like this:
When we save the file, the resulting file size is pretty small: Just 245 KB:
Next, we want to place (using the File->Place menu option in Illustrator) the file “OmahaSkyline.jpg” onto the front cover of the binder mockup:
When we save the file now, we see that even though the image is just linked (and not embedded), the file size still blows up considerably, all the way to 21,481 KB.
We’ll finish the front cover by scaling and positioning the image, and adding some decorations.
If we save the file again, we see that it barely got any larger. Makes sense. The decorations we added are just text and a vector logo, which don’t take up a lot of space.
The Image Is Way Bigger Than Necessary. Now What?
Back in the old days of Adobe Illustrator, the only way to deal with this was to use a “clipping mask” to cut off the un-needed parts of the image. We still use that feature quite a bit, but it is only good for hiding the parts of the image that you don’t need, and does nothing about either file size of image resolution.
A Brief Digression on Image Resolution
Some people claim that you need 300 DPI (dots per inch) to get good print quality, but that’s only partly true. In the real world of printing and reprographics, unless your image contains hard edged elements such as logos, lines, or other such decorations that were added after the fact, 150 DPI is actually more than good enough.
And if your image has logos, lines, etc that were added after the fact, if you really want the best print quality, the right answer is to incorporate those as vector elements in your print file, not to create needlessly high resolution in your raster images.
For natural world photographs, when printed on paper using high volume production equipment using four color process, you will never see the difference between 300 DPI and 150 DPI.
Back To The Discussion
In order to clip away the un-needed parts of that image, we will use the Adobe Illustrator “Crop Image” feature, located in the upper left hand corner of the Adobe Illustrator window. If you don’t see it, use “Window->Control” to turn on the control bar.
The control bar gives you some basic but useful information about your image file, and also provides some controls for manipulating the image. We will use the “Embed” and the “Crop Image” functions:
We start by making sure we have the image selected, then click “Embed”. That action breaks the link between the image in Illustrator and the original image file. Then, press “Crop Image”, and you will see some control bars around the image:
Use those control bars to set the edges of the image where you need them. This eliminates the unnecessary part of the photo:
Next, you can change the resolution value for the image. For print, we recommend at least 150 DPI. As we said before, more resolution than that isn’t necessary. Changing the resolution can be particularly helpful when you start with large images and scale them down them significantly.
When everything is set, hit “Apply” and you’re done! Looking at the final file size, we see that we have reduced it significantly.
This technique is not a replacement for clipping masks. You are limited to square edges and 90 degree corners. If you need to clip an image using some other shape, you still need to use a clipping mask.
If you have questions, we are always available for a call to discuss your custom binder artwork setup job.