It only applies to markdown.
The Rich Text Format (.rtf) stores all information about the document appearance in the file itself. That’s the “rich” part. Markdown is just plain text. It’s essentially an easy way to write simple HTML and keep the raw text more readable.
HTML is also just plain text. It gives a document semantic structure: this is a paragraph, a level 1 heading, level 2 heading, blockquote, etc. The rendering of HTML is controlled by a CSS style sheet. Because of that it’s easy to make sweeping changes to the appearance of documents. That’s one of the benefits of markdown.
From what I understand RTF doesn’t have any underlying semantic information, which makes it a pain to make bulk changes to styling across files. I never used RTF much, so I can’t help you there. I think you can do some things with scripting, but that’s outside my expertise. If you search the forum I think you’ll find something.
There’s a nice introduction to CSS for markdown here on the forum:
The last part of the series is about printing styles.
As long as all your styling use relative units for font-size, setting the base font size for printing with an absolute unit is easy enough:
@media print {
body {
font-size: 16px;
}
}
(16px fits my taste. I always found 12pt too small for printing my own documents. Maybe you’ll like 12px or 14px)
But: You only see the raw markdown in the annotation inspector. That’s why I often prefer RTF here, it keeps links more tidy.