The "curl settled after 3 days" part is the real info here, most people freak out and toss the book when it warps. One thing nobody mentions though, coffee and tea both make the paper more acidic over time, so your nice tan edges might start eating themselves in a few years. A tiny pinch of baking soda in the mix can balance that out if you plan to keep the book long term. Also worth testing on a throwaway first, since some cheap paper turns gray instead of brown when the coffee hits it. Edge painting gives you more control over the color but you lose that natural uneven look that makes it feel real.