White washing boards is one of the easiest paint techniques to do.
All you need is:
raw wood (no finish)
watery paint (it should run like the photo below)
wide paint brush and a large rag
NOTE: any water based paint will work and you only need a small amount
Take your wide paint brush and quickly but completely cover one of your boards in your runny paint
and immediatly wipe it off with your large rag. Repeat for all your boards and let stand to dry.
FYI ... You will get paint on you doing this!
The photo below shows the difference from before and after.
You get to see all the knots and wood grain but you have white boards. When I am using them
for backer boards I do not put anything else on them. If you were to use them as wainscotting where
they would get more traffic and need cleaning you could simply wax them for protection.
Here is another photo showing you how they look in use.
In this first photo the boards in the bottom portion of the cabinet have been painted
solid white and the upper portion have only been white washed.
And finally this is how it all looks finished and decorated.
I love the look and I get to enjoy it every day because it is what I did in the
back of my desk hutch ...