Consolidating pdfs preview the danger of dating online
If you have multiple PDF files that you want to combine into a single PDF file, you can rely on the Macs bundled Preview app to accomplish this.Not only can Preview combine a variety of single or multi-page PDF docs into a single file, you can even add images as pages, remove a page from an existing file if it’s unnecessary to have in the joined doc, or rearrange the pages of the joined files to be reordered according to your needs.Free programs such as the PDF Shaper Free can easily create PDF files from images and then combine them into one for free.But why use a third-party software when it’s possible to combine pictures into one PDF using one of the built-in features in Windows 10?
Preview's "Reduce File Size" feature takes a 512KB file down to 254KB, but makes the text very blurry and difficult to read.
PDFs are funny creatures because Postscript is a very "fat" language; the same PDF can be written multiple ways.
I would say that the extra code is probably glue code to put those three documents together and extra bits placed there by whatever utility was used to combine the three.
I suspect this is caused by images rendered by Preview and re-encoded in a lower compression level. Another possibility is that characters where seen as character in the original file, but are rendered as bitmaps in the produced PDF.
I know that I am years too late to help the author of the original post but I just had this problem and figured it out.
You probably also want to combine multiple pictures into one PDF so that your friends can see all images by downloading just one file.