Print "VOID" on checks generated through payment processing in non-prod instances

Hello

We are trying to see if the checks generated out of non-prod environment using Payment Process can be differentiated from the one from PROD. One of the options we are considering is to use different layouts for prod and non-prod environments and then insert 'VOID' as watermark on non-prod ones. I understand that the payment process uses standard functionality so I cant really customize it to capture the instance name so I am trying to see if there is a dynamic way to achieve the required functionality (differentiate the checks based on instance).

Thanks

Kiran