We have machines that run both direct and indirect contact. Scotty is right on the requirements.
Travelers are identified as Food Grade and include a separate Food Grade Cleaning checklist with cleaning duties and checks for hair covering / beard nets.
Cleaning items are simple, sweep floor, clear any materials from previous job, clean ink trays,etc.
This requires sign off by operator and Supervisor who also checks off items as completed.
There are boundary lines painted on the floor with signs noting authorized personnel only and our GMP's support this.
For storage and shipment we require stretch film on units raw material sheets and finished product. Employees are trained to inspect for any signs of damage to wrap that may compromise the materials and it is written into our GMP's.
Our GMP's are basic covering requirements and apply to everyone all the time with a few tweaks that only apply when running direct contact.
When setting up the system it came down to "what do you do different when processing direct contact, and what records do you have to prove it's being followed?"