I saw on the testors site a technique where you AB panel lines and shadows on planes. I was wondering could you do this by painting instaed of ABing. I would like to do this on a tank so outline all teh recess and hatces to give it depth. Is is better to AB?

I have never tried this technique, but I would assume that it would be pretty difficult. Using the AB gives you control over fading one color into another. If you used the hand-painted technique I would think that would be nearly impossible to get that effect.

IMHO, if I were you, I would stick with using an AB.

Armour66 is correct.Getting the soft edges between the colors is what gives the faded,shadowy look.Painting with a brush would make that more than difficult.Yet,if you are desperate for a challenge,artist tubr oils could give the desired results.You could only do one panel at a time,wait for it to dry,move on to the next panel.This would make for a very tedious paint job that would last for weeks on an average size model.I would suggest investing in an airbrush for certain.

I agree with jackhammer...
Airbrushing sure is the way to go...
When I first started out in this hobby, I did not have a airbrush.
I was sooooo close to giving the whole thing up.. but then a guy at my local hobbyshop convinced me to buy an airbrush... The smartest ting I've ever done in this hobby...

let me clarify: this techniques involves painting the panel line etc THEN AB teh base color over the model teh desired result is that the dark lines look a little darker than the rest of the paint gving the model depth. Thus back to my original quetsion.... :-)

Godfather, yes, you could brush paint the panel lines so long as you paint a little outside the panel's lines onto the panels. Than go over with the AB to "feather" the base color over the overpainted lines. (make sense?...I hope)

Actually I believe its possible to do, dont know how effective it would be. Before I got my airbrush I attempted this with dust etc. but having to keep a straight line might be a little more difficult. If you drybrushed the darker colour in straight lines over the panel detail then with a thinners-dampened (not wet) brush wipe over it agin to spread out evenly the paint. Sort of re-drybrush this out. It will be transparent enough and can be faded into the existing base colour. I have done this with dust on vehicles and have been happy enough with the result.
I use humbrol enamels and humbrol thinner, and leave the base coat to dry for more than 3 days. No paint lifting problems at all. Methods like this were used before airbrushed were common!