[stefanu]

Had similar struggles as well. Then after few experiments with plain paper (tried A4, B6, A5 - all landscape), I switched to Midori Paper Pad, carrying it in a leather pouch. Using A5 on the go and A4 on my desk. All in landscape orientation, like slides. My output is mostly diagrams/schemas and tables, very little prose.

Advantages so far: high quality per that works with fountain pen. No fear of ruining whole notebook with an ugly note or a drawing. I can carry only sheets that are relevant to the problem I am solving right now. I can lay out the sheets in front of me to get a bigger picture. I can throw away the bad ones. It is easier to scan (using iPhone scan to PDF function).

https://md.midori-japan.co.jp/en/products/mdpaper-pad/