The birth cert's currently issued by vital statistics come with a directive that the cert should not be carried and their size and construction material surely don't accommodate carrying the document. They are 7" by 5,7/8" and made of materials similar to our currency. They are the same regardless of the province of birth with perhaps the exception of Quebec.
The above does not apply in BC. Mine was laminated by Vital Statistics when it was issued many moons ago. When DS # 1 got his birth certificate it was wallet sized and came with strict instructions not to laminate it, but it was in a plastic pouch. DS#2 has the large format birth certificate, but we could have ordered the small one. DD has the small one and once again BC Vital stats is laminating them.
Spouse's is from AB and is wallet sized.
Before 911 we crossed the border with birth certificates. A driver's license is not proof of citizenship.