Batman, use "on" in all those cases.
Talking about the t-shirt logo. I say:
I don't like the logo on/in the back.
I don't like the logo on/in the front.
I don't like the logo in/on the front side.
Last edited by B45; 04-Nov-2014 at 03:30.
And omit 'side', unless the logo is on the left side or the right side.
We don't say 'front side' or 'back side', which sounds like 'backside' (one word), meaning 'buttocks'.
You could also say on the side without specifying which side, but front side doesn't work, as Rover says.
For me, the side of a T-shirt is neither the front nor the back. The sides are where the seams are.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.