Just a disclaimer: I'm not replying in vindication, I'm replying to add info from a perspective of a csp user so that op would know the options they have within the program. csp is great to have when making comics, would highly recommend
Typically when making a comic for print, you should work twice the size you want to print.
definitely
Here a little something to look at. I got this from a publisher called kablam. [see image they attached]
in csp you can modify the crop border settings or manga draft settings to make any kind of comic format; be it western standard or japanese manga standard & etc.
I know this is for a manga page, but what ever size you set your page to be at, include the bleed and trim area to your document size. You can always save the cropped image later for posting as a web comic.
in csp, they give you 4 borders: the bleed, crop (aka. trim), inner (aka. live area), and safety margin borders (all explained here). The safety margin is optional among the 4, but the the other 3 are definitely needed and luckily csp has default presets for it. The crop/ binding/ finish border size is the size in which your manga/comic shall be printed. And if you started out twice as big as expected, you could always resize in the export window. But bear in mind that you must always know your crop border/binding/finish size (these terms are interchangeable within CSP).
And yeah you can save your crop/manga border settings as a preset in csp. There are tons of free assets too in csp's asset store (https://assets.clip-studio.com/en-us)
Also: (since I've seen this from a lot of wet-behind-the-ears artists using csp) when you use csp's preset sizes for these borders, don't make the mistake of (as an example) setting the inner border as A4 and the finish/binding size as A5. No. That's not how it works. with that logic, your inner border--the border you put the panels within--will be half as small as the whole comic size that'll be printed. So no, please don't do this.
when sending things for print, make sure you can package your comic as a pdf doc as pages. Don't do spreads, they wont print it if it's spreads, or will charge you to reformat it.
it's okay to make spread pages (two pages are combined) in csp. cuz when you batch export them, csp will ask if you want the spreads to be exported individually like all the other single pages, which you can just tick on or off if needed. iirc, ipads & iphones have a plugin that can export your cmc file into pdf.
but if you have to export them, ask your publisher what formats they require for printing. Usually the format .tif is better, imho.
For coloured pages, you can export them as CYMK and adjust the colours before exporting or saving as JPG or TIF. cuz csp by default only works with RGB profile.
I hope these clarifications helps you in setting up your multi-page comic in csp, @atina1255. If you have any questions about CSP, you can ask me.