Will differences remain while tanning?

Factual Questions
1

I have a “farmer’s tan”: my lower arms and face and neck are tanned while the rest of me isn’t. This is a result of wearing T-shirts and long pants when outside.

However, I find myself going to the beach these days. Can I differentially tan myself so that I even out? If I give myself sun exposure evenly*, will the dark parts get darker as the light parts get darker, or is there a maximum tan that I can attain, and the light parts will catch up to the dark parts? Do I need to put sunblocker only on the dark parts so that the will not tan more?

[sub]*Assume proper use of sunblocker, etc, etc.[/sub]

2

It will all equalize eventually. Enough to fool the naked eye, anyway. No need to mask off body parts.

3

Although masking off body parts might help you achieve an even look sooner - but after you get that, you’d have to stop masking and let everything get darker at the same time.

4

Even if you started out uniformly pale, you won’t ever uniformly tan. Consider the direction of sunlight, and your upright posture. Some parts of you will always get more exposure.