"It will increase profits, market share, and specialisation... it's a great opportunity for both companies, and we hope more may want to join us in the future," said Arrowsmith managing director Philip Cave.
The deal means Cromwell will focus on conventional litho printing and binding and Arrowsmith on digital printing and project management.
The switch involved Arrowsmith moving to new premises and installing a Canon IR125 digital printer plus Duplo finishing kit. Some of the firm's litho kit and staff will move to Cromwell, which will take on 16 staff to accommodate the extra litho work.
Both firms will maintain independent ownership as part of the mutual service agreement.
Arrowsmith in service accord with Cromwell
Academic book and journal printers Arrowsmith and Cromwell Press have formed what the firms believe to be the UKs first print co-operative.