Contrary to what occurs with other products, there is no standard size for ticket printing. Although they are usually printed in smaller sizes for practical reasons. The following measurements can be taken as a reference: 210x98 mm, 210x74 mm, 180x60 mm...
In general, the format to be used should allow the ticket to be stored easily and be easy to be checked when it is used on the means of transport or at the event.
Although, the design obviously does not need to be fixed nor does it have to adapt to any specific standard. And the design must of course be logical.