Business card layout in AI - do it in millimeters or pixels?

Question

Layouts and prototypes

Greetings I
looked at the site about the production of business cards information: width 90mm, height 50mm. And now I'm thinking whether to do the size of the artboard in millimeters (90*50) or can it still be done in pixels (90*50). After all, it's a vector. Is there a difference?

Answer 1

Yes, it is necessary in mm, CMYK.
And also 94 by 54 in size. So that you don’t cut the content on the business card, because. printing knife may deviate by 2-3 mm.

Answer 2

In millimeters, points and other units of the real world, it is better to do what will then be printed on physical media. That is, to have a fixed size, unlike, for example, a site that can stretch as you like. Is a business card a physical object? Physical.
As for CMYK - it is not required for a business card.

Answer 3

When you do a lot of business cards, automatism is developed:
Rectangle 50x90 -> ctrl + C -> ctrl + B -> transformation (from the center) 94x54 -> ctrl + F -> transformation (from the center) 80x40
Inner rectangle - danger zone
Middle - crop
Outer - cutting stock