PLOS publishes the tightest figure spec of any major journal, and it is a window rather than a cap. Width must land between 789 and 2250 pixels at 300 dpi — 6.68 cm to 19.05 cm — height must not exceed 2625 pixels, resolution must sit between 300 and 600 dpi, and each file must come in under 10 MB. Format is TIFF or EPS only. Both ends of that width window matter: a figure narrower than 789 px will print blurry no matter what its dpi field says, and one wider than 2250 px gets resized by production. Above 600 dpi, PLOS states outright that the published figure may be resized, so piling on resolution buys nothing and only pushes you toward the 10 MB ceiling. In practice the workflow that works is: render the figure at your final printed width in pixels, flatten it, save TIFF with LZW compression, and check the byte count. Skwish compresses and resizes the raster image in the browser with a live before/after readout per file, which makes the 10 MB check fast across a twelve-figure manuscript. Nothing is uploaded — unpublished results never leave your machine.