Reblueing Touch Up... what to use?

Have one that's going down the rd. Just need to touch up some areas on the barrel. What is the best agent to use to produce a nice black? Something just in a rub-on product.

Thanks,
A.

I use oxpho-blue creme formula from Brownell's with pretty good results. Ya can reapply to get desired shade and it seems to hold up better than most cold blues.

I've used the Birchwood Casey liquid and cream but not in a long time. 0000 steel wool and good degreaser will also be needed. Guns have gone stainless and/or black anodized aluminum so I've been using Sharpie black perminent marker .

Later,

Aladin, Oxpho blue! It will not remove any original blue like the other touch up stuff does and it blends perfectly. It is almost as tough as hot blue. It will even work if the metal is not perfectly clean.