Equipment based ways to reduce armor check penalty?

[Kraken]

What ways are there to get rid of that last point of armor check penalty on a mithril breastplate without using any traits, feats, or class abilities? Edit: to be 100% clear, I'm hoping to solve the problem purely with WBL.

[Mithril Leaf]

Make it Celestial Armor.

EDIT: Although should you decide to go that route, may I suggest Celestial Mithral Full Plate?

[Kraken]

Is there a celestial template? Or am I limited to the ones that already exist?

[Mithril Leaf]

Is there a celestial template? Or am I limited to the ones that already exist?

There isn't a Celestial Template, but one of the Ultimate books which I can't remember off the top of my head allows you to replace specific magical arms and armor with similar base items. The given example was Leather to Studded Leather I believe.

[Kraken]

Hm, I guess I can try it, though if another option exists, I'd prefer a solution that didn't require negotiating with my DM.

[Fenryr]

If you wish to swim: Buoyant (http://www.d20pfsrd.com/magic-items/magic-armor/magic-armor-and-shield-special-abilities/buoyant).

A somewhat all round (always clean, you may sleep on it, etc.): Comfort (http://www.d20pfsrd.com/magic-items/magic-armor/magic-armor-and-shield-special-abilities/comfort).

There is a 3.5 thingy called Nimble enhancement for armors. Are you allowed to bring 3.5?

[Kraken]

No 3.5 allowed. Comfort looks like a great option, I'll probably go with it unless there's something cheaper out there.

[upho]

Armor Ointment (http://www.d20pfsrd.com/equipment---final/goods-and-services/herbs-oils-other-substances#TOC-Ointment-Armor). Cheap enough if you know a little bit of alchemy.

[deuxhero]

Steelbone Frame (http://www.d20pfsrd.com/magic-items/wondrous-items/wondrous-items/r-z/steelbone-frame). Note that it is fairly heavy though .