I work at a sign/large format print shop. One of our biggest customers sent me a linked file that I needed to download to print. It was a one gigabyte PDF, which surprised me. We often print decals with rasterized graphics for 12’x12’ walls, and those files tend to be around 300-500 MBs. This print job was just for 2’x3’.

It took over half an hour to download, and when it did I opened to investigate. I was expecting Hi-Res photos or original art, but instead it was a whole bunch of white space with some colored text. There was literally no reason it should be a gig.

Turns out, EVERY line of text was a clipping mask to a rasterized solid color layer. I had about a dozen 2'x3’ 600 dpi layers of solid rasterized color.  Turns out that adds up to a GB.

I kept the clipping/text paths, eyedropped their corresponding colors, filled them, and deleted the rasters.  I literally reduced the file to 1/10,000th the size for the exact same thing.