I would like to know- is there any specific rules about packaging to Canada? (I know that the government requirements for labeling are that the languages should be both in English and French and with a specific font) but I don't familiar with the packaging of epacket and HDL rules.
Nick here from Shopify.
I don't believe there are specific ePacket rules for individual countries, but more rules for ePacket packages in general. The main aspect which would change per country is the delivery time. I found a third party article with more information on shipping to Canada which you can read here, but I would also recommend visiting your local post office or calling a courier based in Canada to find out any specifics about what you are shipping to make sure you are doing everything you need to.
Regarding the rules for ePacket specifically, the content team at Shopify have actually written a couple of blog posts and guides about everything you need to know about ePacket and it's packaging which you can read here and here. The ePacket packaging rules can be seen below also.
I'm not 100% sure what you mean by HDL. Do you mean DHL by any chance?
Hope this helps!
All the best, Nick