When I want to make a custom mature emoji, I treat it like designing a tiny poster that has to read at thumbnail size. I start by sketching the concept big — strong silhouette, clear gesture, and an emotion that reads even when it's 32x32 pixels. I personally prefer working in vector for the base because vectors keep shapes crisp when you scale down, then I add a couple of soft raster touches (shading, highlights) on a separate layer. Limiting palette to 3–5 colors and using bold outlines or high-contrast edges helps the image read on dark and light chat backgrounds.
Technically, export multiple sizes and formats: 128x128 or 256x256 PNG with a transparent background is a common default; save a version at 32x32 to test readability. For animated mature emoji, GIF or APNG works for many platforms, while stickers on some apps accept WebP or platform-specific formats. Pay attention to platform rules — some places allow explicit content only in gated or flagged communities, and many forbid minors or non-consensual imagery. If you’re using photos or real people, get explicit permission and blur or avoid identifying features if you want privacy.
Finally, package and distribute depending on where you want the emoji to live. Slack and
discord let you upload custom images directly (Discord animated emoji needs a Nitro-enabled server for wide use), Telegram uses sticker packs (512px and specific tooling for animated ones), WhatsApp has sticker pack requirements and often needs an intermediary app to install, and iMessage requires building a sticker pack in Xcode to distribute. I always test on multiple devices and in actual chat threads — nothing beats seeing how it behaves in the
Wild — and I tweak contrast or simplify lines until it feels punchy. I enjoy the process because making something small that sparks a laugh or an eyebrow raise in a chat is oddly satisfying.