Paper Instruments Launches Ultramarine 1 Flash, an Open-Source Model Built for Professional Document Work at Minimal Cost

Paper Instruments, a three-person AI startup, released Ultramarine 1 Flash, an open-source language model optimized for knowledge-intensive professional work, claiming it can generate business documents—spreadsheets, slide decks, and memos—for roughly 1.6% of the cost of competing state-of-the-art systems. The model, announced on October 14, applies large-scale reinforcement learning to GLM-5.3 Flash, an open base model, to target high-stakes tasks in finance, law, consulting, and operations. On Paper Instruments' internal knowledge-work benchmark, each task costs $0.13 to run—a claimed 60-fold cost advantage over Anthropic's Claude Fable 5 ($8.19 per task) while achieving comparable or superior performance across six evaluation suites.