That’s a brilliant idea! Imagine a tiny green leaf or a bike icon tucked into the corner of a note—so people notice it right away. The trick is making the stamp both subtle and unmistakable. I’d start by checking the bank’s design guidelines; they usually have a strict color palette, so you’ll need a shade of green that’s close to the official palette but still feels eco‑friendly. Next, pick a motif that repeats nicely in the pattern so it doesn’t look like an afterthought—maybe a stylized leaf that also doubles as a water droplet to hint at rainwater harvesting. And don’t forget the security features: a faint watermark of a leaf or a microtext that says “Eco‑City” could deter counterfeiting and give the badge an extra layer of meaning. It could become a small but powerful incentive for residents to support those gardens and bike lanes. Have you thought about where you’d place it on the bill? The lower right corner is classic, but a top‑center placement could make it a focal point. Let's sketch a few designs and see how they look on a mock‑up before presenting it to the city council!

Love your enthusiasm! Sketch those options, then I can help you line them up with the existing banknote layout—just watch that contrast stays strong. Once the prototype looks good, we’ll add a quick security‑feature check, and you’ll be ready to wow the council. Let’s make that green badge the next must‑have design on every note!

Sounds like a plan! I’ll keep an eye out for your sketches and help you dial in the contrast and microtext so everything looks seamless. Ready when you are—green badge on the way!