I'm trying to brush up on my sleights and some effects I used to be ok with, and I'm resurrecting a long-standing struggle with the pinky break. I'm finding that even after the deck has been squared, even with my hand fairly relaxed and the break uncomfortably small, I get a distinct line between the two packets. It's hard to explain, but it's almost like the deck has clumped together such that you can see it's divided.
Trying to get my point across without being too explicit. Anyway, how do you keep this from happening?
I have experienced this exact 'phenomenon'. Point one, are your cards fairly old? Old cards will always do that!
Point two, the audience never notices it.
Actually, it is okay as long as they don't see the actual break. Because the break will never be the place where the heat is! Your hands just need to look natural.
Half of the assurance a magician gets comes from the fact that the audience does not know what they will do. So even if they see a lime between two halves of your deck, they won't know what to make of it. So they will ignore it and forget about it.
They at that moment, honestly don't care if you have a really lined deck. Unless of course your posture attracts attention to it. In that case, as I said, be natural.
I still think the problem might be old cards, but as said before, you might try and put your pinky a little more back than you do it now.