PDFs Are Weird

[drcpunk]

Tonight, I was going through the files from last month that need filing and came on two pdfs of a larp that a bunch of folks wrote a few years ago.

One of the authors sent out the first file. Another asked for a correction.

The first author made the correction and sent the second file. The whole thing, from sending out file #1 to sending out file #2 took maybe 2 minutes. It's not like the first author did anything fancy -- one word was changed.

I opened both files briefly to make sure I was deleting the correct one, and saw that one file was 157 kb and one was 281 kb.

One single word was changed. I do not understand how pdfs decide how big they are going to be.

Comments

[madfilkentist]

Was the correction made to the PDF directly, rather than by re-generating it from a source file? PDFs aren't designed to be changed easily, and a change often consists of appending a new piece to the file.

[drcpunk]

An excellent question. I'd have done it in the non-PDF source document, but I don't actually know how the author did it.

[gorgeousgary]

Well, you learn something new every day...

I've had similar experiences with certain PDF's I create for work meetings. Sometimes, I take a bunch of files, make PDF's, then add a big bold number in the upper right corner keyed to the meeting agenda. This often causes 80 or 90 kb files to become 200 or 300 kb files. I save them again as Reduced Size PDF's and they're back down close to their original size.