Reply by Woodknack

These all seem like reasonable ideas but I ve never been able to get pictures out of the printer in the size that the program says they are.

- 9saws

What program? What pictures? It can be easy or complicated depending on the answers. If it’s a bitmap and wasn’t created full size then it’ll have to be imported into a graphics program and scaled to a known size. If it was created full size then you can tile print. Matthias Wandel also sell a program called Big Print that is probably easier if you aren’t technically proficient.
https://woodgears.ca/bigprint/

-- Rick M, http://thewoodknack.blogspot.com/