One artwork, five surfaces, five separate problems
A layout that works on your 24-inch monitor is not a design yet. It is a design *for a 24-inch monitor viewed at 60 centimetres*. Change the surface and it can fail completely without a single element changing.
The unifying mechanism is simple and worth holding on to: the smallest legible element is set by physical size divided by viewing distance. Everything below is that one rule applied to five very different situations.
The five surfaces
The vertical video, 9:16
Export at 1080 by 1920. The trap is the platform interface, which sits *on top of* your video: captions, the username, the sound label, a column of buttons down the right side, and the caption sheet along the bottom. Roughly, keep anything that must be read out of the top eighth and the bottom fifth, and away from the right edge. These margins differ per platform and change with app updates, so download the current safe-area template rather than trusting any number, including that one.
Two more things people learn the hard way: the first frame is a thumbnail, and most viewing is muted, so anything spoken must also be written. Video editing covers the cutting side.
The feed image
On Instagram, a 4:5 portrait occupies more vertical space in the feed than a square, which is free attention. Text must survive the feed's own compression — thin type at small sizes turns to mush after re-encoding, so err heavier than feels necessary. Assume it will be seen at about 400 pixels wide on a phone, not at the size of your artboard.
The thumbnail at 150 pixels
You upload 1280 by 720. It is displayed, in the places that matter, at somewhere between about 120 and 250 pixels wide. Every decision follows from that: three or four words at most, one clear subject, and enough contrast that it separates from both light and dark interface backgrounds.
The test is not optional and takes ten seconds: after exporting, zoom the image down to about 12 percent, or send it to your own phone and look at it at arm's length. If you cannot tell what it is, nobody scrolling can either.
The printed flyer
Three things reliably go wrong.
Colour. Screens are RGB and mix light; presses are CMYK and mix ink. Vivid blues, bright greens and neon oranges exist on screen and have no CMYK equivalent, so they come back duller and slightly shifted, and the client thinks the printer made a mistake. Convert and inspect before you send.
Resolution. Print wants around 300 dpi. A5 at 300 dpi is 1748 by 2480 pixels; A4 is 2480 by 3508. An image that looked fine on screen at 800 pixels wide is a mess on paper.
Bleed. Anything running to the edge must extend past it, usually 3mm, because the guillotine is not perfect. Miss it and you get a white sliver down one side of the whole run.
The free path here is real but specific. Scribus is the free, open-source layout tool that handles CMYK and PDF/X export properly, which is what a commercial printer wants. Inkscape is the free vector tool for the artwork itself. GIMP and Photopea are excellent at many things and weak at CMYK workflows, so do not discover that at the print shop. If you would rather buy once than subscribe, Affinity's one-off purchase is the usual answer. Vector and print goes into this properly.
The slide behind a speaker
The room is bright, the projector is older than you hoped, and the back row is twenty metres away. Practical consequences: body text no smaller than about 28 to 30 point, very few words, one idea per slide, and high contrast between text and background.
Do not assume a dark slide is safer. On a weak projector in a lit room, black backgrounds wash out to grey and light text loses most of its contrast; in a dark room, a full-white slide is painful. There is no rule that survives every room, which is why the only reliable step is to put one slide up in the actual room before the talk. And nobody reads a paragraph while listening to a person — the slide supports the speaker or competes with them.
The tempting shortcut, and what it misses
Every tool now offers one-click resizing — Canva's resize feature, Adobe Express, various apps. These genuinely save time on mechanical reflow, and for simple layouts they are fine.
What they cannot do is rethink. They will shrink a seven-word headline to fit a thumbnail rather than tell you that seven words is four too many for that surface. They will keep a caption inside the frame while placing it exactly where the platform's own buttons will sit. Resizing moves elements; designing for a surface changes which elements exist.
Do this today
Take one piece you have already published and view it at the true size on the true surface: the reel on a phone with the app open over it, the flyer printed on ordinary paper, the thumbnail at 12 percent zoom. Write down the first thing that becomes unreadable. That is the piece's actual failure, and it will not be the thing you spent the most time on.
Before you move on