How can I improve text on a yellowed/blotched page?

[denzjos]

That's what I did. G'Mic-Qt / Repair / Ian Noise Reduction 2019 (set all sliders to the right), then 'Colours / Desaturate / Mono Mixer' (use the sliders for the best result) and then 'Filters /Enhance / Sharpen (Unsharp mask)'. Then you cab use 'Colours / Curves to optimise (use a S-form curve). As Redraw mentioned, use always a black paper under the page to scan. Click on the picture for the original format.