You can use a USB-connected printer by using the Paperspace app. (Supported on PCs, Mac coming soon.)
Teams with site-to-site VPNs can access their network printers without any configuration. For those without a site-to-site VPN, you can install a client VPN like Zero Tier, Hamachi etc.
For browser and Mac users, we recommend Google Cloud Print or ThinPrint. With Google Cloud Print, you can print out of the box from Chrome or install Cloud Printer to print from any application.