Layout Cammo Pattern

I'm far from an expert, and my models could be considered rather average standard (or below), but I recently did a 1/72 HH-3 Jolly Green Giant with Vietnam era South East Asia camo pattern on it.  It was achieved using an airbrush and demarking the areas with sausages of blutack and filling in the areas in between that I didn't want painted with either masking tape (which I ran out of) or blutack (which I ended up doing when I ran out of tape).

It turned out OK but my blutack sausages weren't quite as good as I could have gotten them, the paint colours I'm not 100% happy with, and I've got a few dark/light patches here and there on the tan colour.  But overall for a 1st attempt it went well I think.  You can see it here -

http://cs.finescale.com/fsm/modeling_subjects/f/16/t/155315.aspx?sort=ASC&pi240=3

The theory in using blutack as I understood it from what I read is that you get a soft edge, rather than the hard edge you'd get with just masking tape and/or normal brushes.  I think I got a harder edge than I should have, but all that I read said you're supposed to airbrush at a 90 degree angle (which I did) to your blutack demarcation, apparently it will feather the edges...

Some people say use paper cutouts of the shapes, but you get the aforementioned hard edge that way from what I've read and understand.

I guess you could even go as far as drawing the pattern on with a pencil and filling it in, but I'd imagine you'd either need to be very good with an airbrush, use a very good quality fine nozzle airbrush, or both.

I've seen a few articles and videos on the web on how to do it and there seem to be a number of methods (most common I saw was the blutack or paper cutouts method though) so it's a case of pick your poison.

Personally I find any method of a difficulty and time consuming level that makes me not want to revisit camo patterns (although not as hard as getting a level coat of Vallejo Yellow (similar to RAF SAR yellow) is proving to be on my 1/72 Sea King), but your mileage may vary.

Here's a google search with some links that may help - www.google.co.uk/search

If you wish to go with a soft edge camo scheme, you can try what I did with my F5 Tiger.  I used Blutack like posted above, but have the pattern cut out and standing off of the model so it isn't directly on the model when you apply the paint.  You will have a somewhat soft edge to the colors that I believe you are looking for.

Here is what the paint scheme looked like after using the soft mask method.

cs.finescale.com/.../159235.aspx

Great responses, thanks for the information all.

Huey 638

silly putty works great for hard non-linear edges. i just, as in 3 hours ago, laid down a ja green over buff pattern on a 1/72 BTR-80.