PencilPlaybook is the UI Skills / Taste-Skill for Pencil.dev + Claude Code — a design playbook that gives Claude real perceptual psychology and senior-level guardrails so it stops producing averaged-out AI slop.

An AI prompt-skill that turns 20 cognitive biases into high-converting marketing copy. Includes playbooks for ads, landing pages, email sequences, social posts, webinars, and product launches. Language-agnostic. Works with any LLM.