Should you be using solid color stain or paint could possibly be the most important question asked by a homeowner. There are some basic differences between exterior solid color stain and exterior paint even you cannot see the difference with naked eyes.
Solid stain is, essentially, a paint. Both solid stain and paint are films that sit on the surface of a substrate. However, a penetrating stain 
entirely differs from a solid stain in which the paint actually absorbs into the wood.
To determine which product is right for an exterior painting project, there are a number of different things to consider. First, you need to consider the surface that needs to be painted – is the wooden surface rough or smooth? A solid stain will work better on smooth surface. On the other hand, a rough surface likely calls for stain over paint.
Here are the basic differences between paint and solid color stain:
Sheen Availability of Paint or Stain:
When beginning your exterior painting project, you’ll want to consider the sheen or gloss level of the paint or stain. The higher the gloss level, the shinier is the appearance and the more easily washable is the finish. Solid color stain is only available in its own sheen. Nevertheless, paint is available in many gloss level.
Application of Paint or Solid Stain:
You can only apply exterior stain on wood that has not been previously painted. But paint can be applied on any wood as well as other surfaces including plastic shutters and stucco. Furthermore, paint will last longer than solid color stain. Stain, on the other hand, will protect the wood better since it lets the moisture escape from the wood. Lastly, solid stains and paints have different thicknesses. Stains are usually thinner than paints.
Benefits of Paint:
There are many benefits of using exterior paint. Paint comes in many levels of sheen and you can apply it on wood, metal, stucco, plastic, and other surfaces. As paint comes in high grade acrylic formulas, it ensures superior longevity. With paint, you can get the brightest and darkest color, which is not possible with stain.
Benefits of Stain:
Although there are some notable benefits of paint, you will always use stain instead of paint in few instances. Stain is more water permeable and it lets the moisture of your wooden deck escape from the wood through the coating. Stain is capable of taking enough food traffic as well.