Dear All:
Masking, except for glass on aircraft and other vehicles stinks. I will never rely on liquid masks, tape or those blobs of goop.
Best thing to do is get a low psi smaller needle and carefully make your own camouflage. I’ve had so many recent headaches and disasters. I know some will say that either I’m not doing it right or whatever . But the fact remains it looks unrealistic, antiseptic and too cute. 
Very seldom mask doing armor models, however when I do Washi Tape works amazingly well for a nice clean edge.
Well, there’s pretty much no way around masking if you’re doing splinter or digital camo unless you’re going to do it all with decals. When I do mask, I always de-tack by sticking the mask to my jeans first, before placing it on the model.
Many of us don’t have steady enough hands to get our lines perfect with free-hand painting, in which case I will sometimes use masks on top of small blobs of blu-tac in order to get a good feather edge.
I get everyone has their preferred methods for doing things, but it is also true that sometimes circumstances require us to use other techniques to get the result we want. “Never” is a pretty strong word in the modeling business.
Okay, I mentioned this elsewhere.
Many years ago, I built a Tamiya T-34-76 and the finish I chose was a green and brown scheme.
Being the lazy goof I can be, I looked at the prospect of masking as a real bother.
So, what I did was set my Paasche V1 at a very fine setting and demarcated the edges of the colors. Filled in the colors.
Next, I took a Q-Tip and dipped it in thinner and rubbed the demarcations.
I was really surprised. The effect was of a very realistic hand-painting and not the harsher sometimes unnatural edge along different colors.
Try it and you will see what I mean.
Hi, just get in because I am one of those using masking when it comes to sharp edges. I cut my own shapes from masking sheet, warm it gently to make it adhere to the surfaces. It takes time and I have fun. That’s enough for me.
Cheers
HAHAHA! I have so much trouble spraying camouflage with my airbrush that I mask whenever possible!
Hello!
I’m working on this baby:
Now the “big” colours (green and drab) were done freehand, but the “small” colours (“black” and sand) were masked with patafix - putty like compound that’s very good for masking to get that not-really-hard edge. I recommend it heartly.
Good luck with your builds and have a nice day
Paweł
Yep, that’s how I do it.
The black masking putty spreads as you go which isn’t helpful, and will efficiently remove any small greeblies or PE you have put on there. I’m not a fan. If you take your time, use a small needle and drop the pressure, understand how keeping the nozzle perpendicular and being super gentle on the backpressure flow can reduce overspray, it is possible to get very nice hard edged camo freehand.
Its not quite a precise as using masks but its not far off and I kind of like the effect.
Reminds me of a house tune I used to play out all the time back when I was a DJ in London and Dubai, almost 20 years ago now.
NATO camo?
Drop the pressure!
I’ll give it a try, thanks.
Usually there is not a single, right, way to do things so each one choose according to personal preferences.
In my case, I have no problem at all using Ammo masking putty. Applied in thin layers it keeps the shape long enough to paint, produces perfectly hard edges effortlessly and it is easy to remove without leaving any residues.
As often you have some freedom to paint the camo, it is not hard to move the lines a few mm to avoid the most delicate PE parts.
Horses for courses, depends on what you are doing I guess. If I can possibly get away with freehanding the camo, I will do. If it requires the hardest of hard lines then I’d likely use tape masks or give Washi Tape a go, like Wade suggested.
I’m just happy I have the choice. When I first started modelling, I wouldn’t have been able to do any kind of edged camo with an airbrush to save my life. I have tried brushpainting camo in the past and always regretted it.
Some camouflages are impossible to reproduce without masking tape (for me), such as Swedish tanks. See my STRV-103C
http://www.puttyjet.com.br/galeria/mil/strv103c_03.jpg
Back in the day before folks started using putty type masks modelers would use masking tape laid out to the desired curvature of the different color and roll the edge of the tape to raise the edge about an 1/8th inch, you then airbrush at an angle AWAY from the edge to achieve a feathered edge. Some artists simply hold a piece of paper above the surface and with quick “shots” move the paper to create the desired edge, this takes a bit of practice though, I’ve tried it and it’s not so easy to pull off. I agree with you though Daniel @Sladenyv, a smaller needle and lower pressure may be the easiest technique for scalloped or curvaceous edges in most cases. Your wrecker looks pretty darn good to me though, nothing to be ashamed of by any means.
Cajun 
I used to use cardboard masks with random lines cut out for German three colour camo when I was a kid. But that was before I purchased a decent airbrush with interchangeable nozzles. Now I freehand with the fine nozzle. Most of my schemes are “generic” and looking at period photos there is frequently a lot of “over-spray”. But I’d have to give some thought to this if I did, say, an aircraft with set camo pattern.
That is STUNNING.
And yes, masking most definitely required there hahahaha
Objection! Being mostly an aircraft modeller I (and no one else) can’t achieve this …
… without a lot of masking tape …
… even for amor builds it is sometimes essential, like on this Finnish K9 Moukari …
… to come finally to this result …
Building scale models is nothing for impatient people …
I fully endorse your last sentence 
By the way, what is the thin green tape of your picture? I like the results pretty much!
Thanks Stefano! 
The green tape is no Washi Tape but 3 mm polymer tape, called Fine Line. But it is available in different width. It has about 50 meters on the roll. I have 3, 6, 9 and 12 mm here and get it from a shop in Germany. Maybe you can get it also somewhere in Italy.
Thanks a lot, I’ll see around.
