I’m the author of PrintStack.

I built this because I found the workflow for combining documents on macOS frustrating. If I wanted to merge a receipt (web), an invoice (email), and a contract (Word), I had to "Print to PDF" each one to the desktop, open them in Preview, and drag them together.

How it works: PrintStack runs a local virtual printer server on your Mac. You can hit Cmd+P in any app, select "PrintStack," and the job is captured by the server and sent to a background queue. It acts as a buffer—you can keep pushing jobs to the stack and then merge/export them all at once as a single PDF.

Pricing: It's free to use for batches of up to 5 documents (which covers most casual needs). For unlimited batching, I offer two options: a Yearly Subscription or a Lifetime one-time purchase (for those who hate subscriptions).

Happy to answer any questions about the virtual server implementation or how it handles the print stream!