Sims 4 ships with a handful of tattoos that haven't been updated since 2014. They look it. If you want ink that actually reads as a real design at CAS distance — a fine-line flower on the collarbone, a sleeve that wraps properly, a single small piece that doesn't pixelate when you zoom in — you need community tattoo CC.
This collection is smaller than the hair or clothing grids (about a hundred mods) because tattoo CC is a narrower niche, but it's one of the categories where the drop in quality between vanilla and community content is most obvious. Creators like Pralinesims, Sims3Melancholic, and remussirion have basically carried the scene for years.
You'll find sleeves, back pieces, small minimalist ink, and a handful of full-body sets. If you build story-heavy sims, tattoos are one of the cheapest character-building details you can add — a single well-chosen piece communicates more about a sim than half the traits panel.