The phrase describes the availability of skeletal diagrams in a portable document format (PDF) that can be obtained at no cost. These digital files are designed to be easily printed, providing a tangible visual aid depicting the bones of a human or animal.
Such resources offer notable advantages in educational settings, allowing students to study anatomy without requiring expensive physical models. They also benefit artists needing accurate skeletal references, or individuals pursuing personal learning. Historically, anatomical illustrations were painstakingly hand-drawn and costly to reproduce. The proliferation of digital formats and online distribution has democratized access to this type of information.
