I have a question for all of you diorama building maniacs ; Why do modelers paint dirt to make it look more like dirt? I have been building models on and off for about 20 years now. I have done only few dioramas so naturally I do a lot of research on techniques that others use, trying to learn new tricks. One thing that I see time and time again is that after a layer of dirt (actual dirt from outside) is applied it then gets painted, repainted, dry brushed, washed and so on and so forth. I ask this question, WHY? What is wrong with the natural color (grayish brown) that dirt comes in? The only time I would see a reason to paint the dirt is if the dio theme places it somewhere in Vietnam where dirt was orange/red clay or some other place with weird colored ground. I guess, I am just curious.

Cheers
Marty

Marty,
Here's my take and my experience on Painting Dirt.

Dirt Source and Scale have a lot to do with it. For me here in North Carolina if I use true dirt I don't get much variety in color and the dirt I get may not match the location I am depicting. My dirt tends to be very red from clay or tan from sand.
Scale, think about flying over a landscape in a plane, you see a lot of different fields and shades and colors of green or brown or yellow (depending on if you're flying over forests, plowed fields, or corn fields) as you get close to them walking or driving the number and shade differences reduce and blend together. Same with the non painted dirt. What modelers are trying to do is put the variations back into the dirt by painting it. It also can help visually with 'flow' of how you view a dio, directing your eyes to the subject. More colors give greater depth and richness a subject too.
Hope I explained it well enough.

I'd say the same as Slodder : scale effect... And also, where I live, the dirt is not necessarily
the same color as the one found in Italy, Ukraine, Afghanistan... Also, if you want to represent mud, there
are still more color variations...
Which means... plenty of fun for those who love dios !
And where would the fun be if you just applied dirt and leave it this way ? It would be the same as gluing
2 parts and saying : there, I'm finished ! That's not for me !
Paint is fun !
Dirty is beautiful !
Small is cute (I love softskins) ! #:-)

I have to go along with the other's.
I use washes & pastels to give added depth to the diorama.
And also, as far as I'm concerned, I research the specific country
and the landscape/battlefield that I will use for my diorama.
......Hence, the washes, pastels, and any other weathering techniques,
are used, so I can try to give the best overall depiction of the landscape
and it's enviroment the way it is seen in any photo's I use for reference.
Also the time of season ( winter, spring, summer, fall ) play's a major factor
of gathering the needed variety of colors that will be used for painting added
detail that gives depth, contrast, to plain ordinary dirt, and
solid colored packaged aftermarket landscape accessories.

- ralph

There is a simple reason for painting the ground, everything else is painted and if the ground wasnt painted it would look unnatural compared to everyting else.

Let me take this a step farther... another consideration of "dirt and weathering" is the structure itself... a tank is going to have rust... a building with wooden siding or shingles is going to have grey aged stains - while a building with a Tin roof will have a mixture of black (oxide) and rust run-off. This will also be absorbed differently by different surfaces... the mortar in bricks and the stucco on the side of a wall will (typically a light color such as tan, white, beige, etc.) will show a "darker" stain... things like this mean you need to consider tinting the color of your "mud"... it is not an exacting science... more of a "looks right / feels right"... - Keith

Thanks for your responses. I guess I will be coloring my dirt too.

Marty

Would the paint also acts as a seal and chemical barrier for gems and small insect get into the actual dirt? Don't want a gigantic ant crawl out from the dirt and climb on the tank, do we? #:-)