Coal Seam

Coal Seam is black anthracite, glow. High-contrast, utility-first, with the visual weight of something that ships in crates rather than packets. Bold display type, a single industrial accent, and a layout that reads as schematic rather than scrapbook. Looks like it was approved by a project manager, which is a compliment if you sell into anyone with a hard hat.

Good for trades-focused apps, industrial IoT platforms, logistics tools, and B2B brands that smell faintly of metal, oil, and ambition. Bad for boutique skincare, premium food, or anything where the customer wants to feel pampered, soft-handled, and walked through the experience by name.

Free covers referral tracking and CSV export, which is genuinely enough for the first thousand signups. Upgrade to Pro for a clean custom domain that matches your brand and broadcast emails that go out the moment you press send, which together cost less per month than most teams spend on a single design tool.