As others have posted, I use Apple's Smart Cover on my iPad both current and in the past. I like the clear rubbery cases from
Luvvitt found on amazon. (Since I knew I was going to buy the iPad for a while, I ordered the case so it was in hand when I bought the iPad and my local store. The case cost
less than 15 dollars, and have not deteriorated in any noticeable way (meaning the material has not yellowed with exposure to light). Being clear, I can put a home made sticker between the apple logo and the case (I don't feel a need to advertise the apple logo since I am not getting paid by apple).
If I am going to wear a corporate logo, or walk around with it, I expect to get paid.
I bring my iPad everywhere from home, work, school; and yes, the local coffee shop. There are no noticeable marks on the Smart Cover, Luvvitt case, or iPad. But then again, I bought this very expensive device so I take care of it, and don't drop it.
I do have a relative in the construction business and uses his iPad Air 2 (with the same case) in the field for taking photos of the job site when creating field reports job quotes and such. He has told me his device is scratch-less condition.
These are all expensive devices, take care of them and you don't need military grade cases to protect them. Nor do you need to pay a lot for a fancy branded case.