Hi João,
sorry for the late response - i over-read your question. The normal way the Matukio certficate system works is that after the event you can certificate your users (this can also be set to automatic if you like) , so that they can download their certificate (simple HTML Code with placeholders (for example MAT_EVENT_TITLE will be replaced through the events name, MAT_BOOKING_NAME with the participants name etc.) like on the Bookingmails.
Of course you can also certificate your participants manually and then download / print the certificate for them in the Matukio backend. You can 100% customize it to your needs (And you have all event and booking data in the placeholders), pre-printed paper will work fine also.
You can also find some more details at
compojoom.com/support/documentation/matukio
One more question, is Matukio responsive?
What exactly do you mean with responsive?
Best regards,
Yves