I've been looking over and studying how books differ in page and font sizes. Is it the publishing company that decides those two factors?
I don't think that they do, I think what happens is that if your font is too big it will produce more pages and that means more money you have to spend. If you get offered a lot for your work then it is not a problem, if you don't and you have a large font, you have to put your own money into the book to have it printed or your agent will recommend that you put it at a standard font. My father in law, brother in law, and my husband are all in printing and I can ask them for a for sure answer for you, but I think that is how it works. What size of font are you using? If you are trying to fill up chapters i.e your work is 15 pages long and you double sided that will give you 12 page and a half chapter, you could see if you can combine your chapter together so Chapter 1 and 2 becomes chapter 1. I had to do that with mine. I would have only had a 5 page chapter. But it is your writing and there are books out there that have small chapters. The font is up to you depending on how much money you want to put into it and if you want to put money you didn't get from your offer into it. But it is per page. I hope this will help.
That font and size can be good reflection of what the completed project will look like, but you can't count on it. Also, while it is becoming more common, not all agents and publishers will accept it.
I'll keep the answer simple. Yes. And the hardbound edition will probably differ from the softbound one. You shouldn't worry about pagination as a writer. Leave tha to the typesetters.
Aren't all costs met by the publisher if a novel is being commercially published? As far as submissions go, most publishers/agents specify fonts and sizes in my experience. Or are you referring to self publishing? Not having a go, just confused...
Unless the book is self-published, the author generally does not decide what font/size/spacing and book size will be used (ie different sized hard cover/trade paper backs. mass market). The publisher is the one that takes care of that. Terry
...of course they do!... see cog's simple [correct] answer to the question... ...i have to assume chandler's comments refer only to self-publishing, but the op seems to have been asking about author-paying publishers...