What binding options are there for an A3 sketchbook that I can rearrange or add pages to? I want to start a project sketchbook where I will put all of my existing notes for 1 specific project, separated into different sections, and with a table of contents, to arrange them and have a central point for my notes on that project.
It will mostly be text but will also include process flow diagrams and pasted photos, so I want plain paper without printed lines.
I want it to be A3 size, and I thought of getting a plain A3 sketchbook, but there may be a time where 1 page is not enough for a specific section that is between other full pages, so I wonder what options there are for something so I can add a new page in the middle.
You can make your own sketchbook ring binder:

That way, new blank A3 pages, as well as coloured index tabs, can easily be added anywhere.
You can perforate new pages yourself using a hole puncher.
If your project files consist of a lot of loose or thick objects, you can also opt for a binder box.