The concepts
These are general printing concepts.
- Trim edge. The line along which the paper is cut; it marks the final size of the page (trim size).
- Crop marks. Small lines outside the page that indicate where to cut.
- Bleed. The part of the drawing that extends beyond the trim edge. If the cut drifts by a few millimetres, no white edge is left.
- Safety margin (safe area). The area inside the page where everything important, such as text and faces, must stay. If an element lies outside it, the cut may take it off.
Clip Studio Paint documentation
CELSYS, the company that develops Clip Studio Paint, explains in "Basics of creating a manga manuscript" (19 April 2018) the inner border, crop marks, trim edge and bleed, and warns that essential content must stay inside the safety border. It also covers manuscript size, resolution and colour depth or mode, but gives no single universal value: they depend on the printer and the destination.
CELSYS also documents print presets, including Shueisha presets since version 4.0 of Clip Studio Paint and one called "For commercial issue Bleed 3mm" for certain destinations. These are example settings, not a standard for your printer.
Reference values
The values depend on the printer. As a reference, a Spanish printer, Bloprint, gives on an undated page a bleed of 3 mm, a recommended safety margin of 4 to 5 mm, 300 ppi, CMYK colour and PDF/X-1a or PDF/X-4. It is a commercial source and not a specification specific to comics, and it gives no particular colour profile. Treat it as guidance, not as a rule.
I have not found dated specifications from a Spanish printer or publisher specialising in comics.
Questions for your printer
Before you start drawing, ask and get the answers in writing:
- What is the final page size and what is the size with bleed?
- How many millimetres of bleed do they require?
- What safety margin should I allow?
- At what resolution, in pixels per inch, must I deliver the files?
- In CMYK, in greyscale or in pure black and white? Do they ask for a particular colour profile?
- In what file format, and one page per file or a single PDF?
- Do the spine, cover and endpapers have to be supplied separately?
- Do they have a template?
With those answers, set up the canvas in your software before drawing the first panel. Changing it afterwards means reframing every page.
For final files, colour profiles and delivery to the printer, see How to prepare a file for printing. To keep your master files, see What to retain as a master file for a digital work and how to name its versions and Master artwork record: annotated template. If you print on your own account, see Selling your fanzine at a fair: requirements, costs and what remains to be confirmed; if a publisher publishes you, see Publishing contract for a comic: mandatory clauses and the author's rights.
And for screen display
The official WEBTOON CANVAS help centre (section "Publishing Your Series"; documentation updated on 22 July 2026) publishes specifications for thumbnails, not for episode images:
- Square thumbnail: 1080 × 1080 pixels, less than 500 KB, in JPG, JPEG or PNG.
- Vertical thumbnail: 1080 × 1920 pixels, less than 700 KB, in JPG, JPEG or PNG.
- Episode thumbnail: recommended 202 × 142 pixels, less than 500 KB, in JPG, JPEG or PNG.
For the images that make up the episode, an official WEBTOON notice of 18 May 2021 sets a maximum size of 800 × 1280 pixels per image and says the system automatically crops and optimises long vertical images. It is an official source, but from 2021, and it does not give the maximum file size or the accepted formats. Check the platform's current help pages before preparing your files, because these specifications change.
To choose where to publish, see How to publish a webcomic without relying on a platform.
Points requiring clarification
- Dated specifications from a Spanish printer or comic publisher: bleed, resolution, margins and colour profile.
- The maximum file size and accepted formats for WEBTOON CANVAS episode images. An official series hosted on the platform, from 2017, mentions only JPEG, but it is creator content and not the current help centre.
- Whether 300 ppi, 3 mm and CMYK suit your case: they depend on the provider, the final size and the binding.
Itineraries
I am starting my practice
Before drawing your first page for print, ask your printer two questions: the size with bleed and the safety margin. With that you can create the template in your software.
An open conversation
This guide sets out what is documented and leaves open what depends on each printer. If you work at a printer or a comic publisher and can share its specifications, you can write to me.