I couldn’t agree more!  Very thin paint, low pressure, and practice, practice, practice!  

Steve

What they said and get close to the subject.

What they said and...don't be so quick to discard the masking idea. You don't have to go expensive: ten minutes with a craft knife and a piece of stiff paper will give you a very useful mask which really isn't that hard to use...easily tacked in place with little bits of Silly Putty or something like Blu-Tack.

I'm not dumping on learning your 'spray' technique, by any means...but masks are another very useful tool to have in your arsenal.

My first and second attempt came out O.K. It was intimidating at first but from my experience it's something that has to be practiced in order to be learned. I concur with everyone else that the pressue needs to be very low and the paint thinned. As I paint I look for the paint to wet up on the surface and move the airbrush at a gradual speed in random strokes to make the pattern. I keep the airbrush moving and I keep the air running the whole time pulling back on the trigger to add paint and letting go between spots.

Also, if you happen to to put down too much paint which I did, you can always go over with a thin layer of the base color to even out the tones.

tempestjohnny

A great homemade mask is a 3x5 index card. Make a jagged hole or holes and spray with low pressure

 

If you're not comfortable doing this freehand, then what TJ mentions should work well.

It also depends on your airbrush.  If you are using a single action siphon feed, you will never be able to get it fine enough to do that type of airbrush work. This type of airbrush typically needs 12-15 psi just to suck paint out of the cup.

At minimum you need a double action gravity feed with a .2 needle setup.  This type of airbrush will allow you to shoot up close, I mean 1/2" or less from surface at psi under 10.  Sometimes I take off the cap that protects the needle to get even closer.  This takes practice.  both working with the airbrush and how you thin your paint.

If you can get a hold of an airbrush like a Iwata micron, Badger Sotar or similar that goes down to .18 and .23 needle size, now you get the kind of control that will put you at a whole new level of airbrush work, but these airbrushes are not cheap.  I think the sotar is on the lower end priced at $200.  Microns are at $400-$500.

Otherwise as mentioned creating masks to some degree or another is the other way to go if your airbrush is not the right setup.

Yeah, I've used the index card trick successfully.  I remember that from the old Revell Master Modeler newsletter, of all things.

route62

...At minimum you need a double action gravity feed with a .2 needle setup.  This type of airbrush will allow you to shoot up close, I mean 1/2" or less from surface at psi under 10.  Sometimes I take off the cap that protects the needle to get even closer.  This takes practice.  both working with the airbrush and how you thin your paint.

If you can get a hold of an airbrush like a Iwata micron, Badger Sotar or similar that goes down to .18 and .23 needle size, now you get the kind of control that will put you at a whole new level of airbrush work, but these airbrushes are not cheap.  I think the sotar is on the lower end priced at $200.  Microns are at $400-$500...

How would you set the needle, Route62?  That is, how far would you let it stick out or how far back would you retract it?

I set the needle to be pressed in all the way till is is seated up to the nozzle.  I would rather start from 0, fully closed nozzle so that I have full range from closed to fully open nozzle.  I use the adjustable stop on the back of the airbrush if I need to make sure I do not open the nozzle toomuch. Usually for very detailed up close work like the Luftwaffe mottle camo.

route62

I set the needle to be pressed in all the way till is is seated up to the nozzle.  I would rather start from 0, fully closed nozzle so that I have full range from closed to fully open nozzle.  I use the adjustable stop on the back of the airbrush if I need to make sure I do not open the nozzle toomuch. Usually for very detailed up close work like the Luftwaffe mottle camo.

Thanks!  That's one thing I find missing from many discussions about airbrushing-setting the needle.  I want to learn the optimal position for different kinds of painting.

I have a single-action airbrush so I use friskette paper or a coffee filter with random small holes punched. I tack it down with blue tack doing small sections at a time. I set the needle as fine as possible and drop my pressure as far as I can, usually around 12-13 lbs. it works pretty well for me.

this is my Zoukei Mura Ta152.

It is also, believe it or not, my first go at mottling.

All I had was the correct colour(s) from Vallejo. I didn't thin and used a 0.02 needle in my H&S airbrush. I kept the air pressure the same that I normally have it at and just worked very close under a bright light.

Mottling is a very irregular thing and all you have to remember is not to go full depth with the paint. It is there to break up solid colours and to confuse the eye.

Three is no set pattern and so long as you stick to the corerect upper surface colours then just keep the airbrush moving once the paint appears.

The aim is to put something on to make the eye keep moving and to helo break up the outline. 

The human eye and brain registers colours and patterns. With the pictures you put up you will note the effect by making yourself be aware on your eyes constantly moving over the two images while your brain tries to sort out a pattern... and it can't because it's a random colour(s) over a lighter background with no definite edge or depth to the random colour.

Your eye will focus on the insignia etc as they are a definite shape and recognisable pattern with edges.

Just get a piece of thick paper and hit it with your airbrush at different nozzle openings and distance to get your brain, eye and hand co-ordinating so you can get used to just how your paint flows and the patterns that you can create.

Once you figure out the hand-eye-brain thing and understand the connections then painting gets much easier!

Mottling on Luftwaffe models is not a case of trying to replicate a pattern it is a case of putting random colours over a block background in no destinct shape and to fool the viewers eye and brain. They will see something is there and the brain will spend most of the viewing time trying to figure it out and adding colour subconciously to try and help.

Don't believe me? try it on an old kit or the one your doing and ask someone to look at it and just watch their eyes and their movement.

 Painting Mottling Without an Airbrush

https://youtu.be/aSfSAqw6Kx0

Mottling can be tricky, but as others have said, thin paint and low pressure. 

Also, for me, I do not use water based acrylics... it is too hot and dry in my location to use them without lots of tip dry and clogging problems. So, for me its Tamiya.

And I can't use a regular double-action airbrush any more; I just don't have the smooth dexterity I used to. So, I switched to a trigger-style airbrush. I got an Iwata TRN-1 and the control is unbelievable. It has totally changed my outlook on aircraft painting in general and camo/mottling in particular.

My first attempt at mottling is done. I used pieces of post it notes with holes cut in them to create masks. The mottles were too dark but I oversprayed them with light blue to make them blend with the rest. Not perfect but better than having overspray all over the model.

Looks pretty good there MZ! I do what others have mentioned and went with low pressure but with the needle barely open and just keep the AB moving. I've also done what you did with going over the whole mottle pattern with a thin coat of base color. That looks like an Eduard 190 you're working with right?

Man, when I tried mottling for the 1st time, it looked TERRIBLE! Yours looks pretty good! I think pretty much the only way to get great mottling is to just practice a lot and to have a good airbrush.

However, I saw a guy who blended some pastel chalk powder/shavings to get the correct color, took a fine brush and slowly built up the mottling by adding thin dust layers, just like how you'd add exhaust streaks. Then he sprayed Pledge over it to protect it. It looked just as good as the best airbrush jobs I've seen. I've never tried it, but you might want to if it's any easier for you.

I have come across mottling in decal form on ebay. This might be the easiest and less stressful of doing it.

Your mottling turn out great Monster.

I personally don't lower the pressure on my AB, for me that leads to spitting. I use very thin paint, very close to the subject and very light on the needle. I spray on a paper towel first to make sure I have everything correct and clean the tip offten.