How do I find a printing company for custom designed papers?

so that type of printing you are looking to do - is well very expensive and many places that do it arent neccessarily advertising it- for printers money is in the 4color process high speed quick printing-

so - your art could be printed 4 color process- but the paper is gonna kill you- cause printers make you buy the whole roll or qy they have to purchase so they dont lose dolla$. And printers would want to do high quantity- if you are looking for low quantity in a 1 or 2 colors try the phonebook and look for "offset printing" it smaller presses and you can usually do smaller quantities of 500 -1000

to be honest- unless there is a high-end niche target market, you may want to look for another avenue of business. becuase ac moore and micheals and all those have lot of designs for a fraction of what it will cost you- sorry hate to be debbie downer- but i know the print industry (worked on presses for a few years and the company i worked for would never take this project on unless in major quantities and we werent a big company)

regardless.... all the best and shoot for the stars!