How to get my Mac (High Sierra) to recognize custom Quartz filters I created to reduce file size? I want to create custom Quartz filters to reduce file sizes to custom specifications when exporting a PDF in Preview.
I found a helpful article on how to do it with an old operating system.
I found the code to modify here on Ask Different: How to decrease .pdf size without losing quality
My only problem is I can't get my Mac to recognize and use the custom files I created. It looks like the file structure has changed as Mac has upgraded its operating system. I have tried placing the files in the following locations and none of them have worked.
Library/Filters/ (created a new Filters folder)

Library/Users/my_user_name/Library/Filters/ (created a new Filters folder)

Library/PDF Services/

Library/PDF Services/Filters/ (created a new Filters folder)

System/Library/Filters (not allowed to edit)

This was my reference, macrumors.com, for where to place the files.
I am running High Sierra 10.13.4.
I have had success on macOS High Sierra 10.13.4 with putting Quartz filters in a Filters folder within my user's Library folder:

/Users/my_user_name/Library/Filters/

in other words:

Macintosh HD &gt; Users &gt; my_user_name &gt; Library &gt; Filters

However, your Library folder is normally hidden. An easy way to navigate to it is to click on the Go menu in Finder and while the menu is down hold the Option key. Library will then appear in the list. Once you open it you can create the Filters folder which probably doesn't exist, and put your filters there.

For reference, the filters I am using are those that Josh Carr posted to GitHub.