Flip Your Drawing to Check Mistakes: Build Your Own Tool
If you’ve ever flipped a drawing horizontally and suddenly seen every wonky proportion you missed, you already know the trick works. The question is how to make checking your work this easy every time — without relying on a generic app that doesn’t match how you actually sketch.
Why flipping your drawing exposes mistakes
Your brain gets used to a drawing the longer you stare at it. It starts filling in gaps and smoothing over errors that are obviously there to a fresh eye. Flipping the canvas — or mirroring your reference photo next to your sketch — breaks that familiarity. Suddenly a face looks lopsided, a limb looks too long, a building looks tilted. This is why so many artists ask why does my drawing look wrong when flipped: it’s not that the flip creates new errors, it’s that it removes the mental shortcuts that were hiding them.
The mirror trick to check drawing proportions works the same way as flipping canvas to find drawing errors — both force a proportion comparison your eye can’t fake. But doing this manually means juggling reference photos, flipping images in a separate app, and eyeballing overlays. Search around and you’ll find generic mirror or flip tools, but nothing built around your actual workflow of comparing sketch to reference side by side.
That’s the gap building your own Frame in Auto closes.
Build your own proportion checker in Auto
Auto lets you describe the exact tool you want and builds it around a photo you snap. For this concept, you’re not just flipping one image — you’re overlaying your sketch on its photo reference so you can catch proportion errors directly.
To build yours:
- Open Auto and describe the comparison tool you want. Mention that you want to upload a reference photo and a sketch, and see them overlaid.
- Snap or upload your first pair. Auto uses this to understand the images it needs to handle.
- Ask for the controls you actually need — selecting which image is active, moving it, scaling it with a pinch gesture, keeping a storage area for everything you’ve uploaded so you’re not re-uploading each time.
- Refine it. If something doesn’t behave right, just describe what’s wrong. Auto fixes it in the background.
The result is a Frame that’s yours: built for how you compare sketches to references, not a generic flip button bolted onto someone else’s app.
How someone built theirs
One Auto user started simply: they wanted a frame to compare sketches against photo references for finding and correcting drawing mistakes, with a storage area for uploads, the ability to pick a reference and a sketch, and an overlay view where you could select an image and move or scale it with two-finger gestures.
Auto built a first version, but a build error came back — touch event types weren’t matching up, and a selection component had a prop mismatch. The user pasted the error details back in, and Auto fixed the type issues and the broken selection logic without the user needing to understand any of the code. This back-and-forth — describe, build, fix — is normal, and it’s exactly how “Sketch Compare,” a real Frame built this way, came together.
FAQ
Do I need to know how to code to build this? No. You describe what you want in plain language and Auto builds it. If something breaks, you describe the problem and Auto fixes it.
Isn’t there already an app for flipping drawings? There are generic mirror and flip tools, but they don’t let you store references, overlay sketches, and scale them together the way your own Frame can.
Can I keep adding features later? Yes. You can ask Auto to add zoom presets, opacity sliders, or side-by-side view whenever you think of them.
How long does building one actually take? Most people get a working version in minutes, then refine it over a few more prompts.