Is this the same as dull coat?, What effect does it have on the finish?

Not exactly, it's really a kind of white/tan and it is a paint. If you're looking for a ture dullcoat I suggest Testors Dullcoat, it's a laquor and works really well IMHO. But I find most Tamiya paint dries flat enough that a dullcoat isn't needed.

Nate
Wisc. USA

No, this is a colour coat (a light beige). A very useful shade for simulating dust.

I use it to finish off vehicles. I spray it all over the whole vehicle. It adds a realistic dust like finish, ties all colours together and dampens down anything that would stand out too much. Steve Zaloga who writes for military modelling uses it like this as well. (I guess thats where i got the tip from in the first place). Mix 25% buff, 25% tamiya clear X-22 and 50% isoproponol. It sprays almost clear and does dull the finish. A light coating on top and higher sides, and a few passovers nearer the bottom, gives a very realistic dust finish.