If you have a spray gun, you can use it to create an entirely different look on the wood than you get wiping or brushing the stain and wiping off the excess. Simply spray the stain and leave it; don’t wipe off the excess.
The key here is whether or not you wipe off the excess, not how you apply the stain. You could also spray the stain and wipe off the excess. But you can’t get an even coloring by wiping or brushing the stain and leaving the excess. You can’t help but leave more coloring in some areas than others. Only by spraying can you get an even coloring everywhere.
The trick is to thin the stain a good deal (say three-to-six parts) with the appropriate thinner and build the color slowly with several coats. You can spray the coats on top of each other while still damp, or you can wait until each coat of stain has dried before spraying the next.
If you try spraying just one coat of full-strength stain (rather than multiple coats of thinned stain), you’ll have great difficulty getting an even coloring. In fact, I feel comfortable saying that unless the object is small and flat, you won’t get an even coloring. You have to thin the stain and apply multiple coats.
You can see from the accompanying photographs the difference spraying and leaving makes. I used the same stain on both sides of both panels.
On the oak panel, I wiped off the excess stain on the left side, and I left the thinned, multi-coat sprayed stain unwiped on the right side. Not wiping off the excess stain caused the oak grain to almost disappear.
On the pine panel, I also wiped off the excess stain on the left side, and I left the thinned, multi-coat sprayed stain unwiped on the right side. Spraying and leaving reduces blotching to almost nothing, but it also muddies the contrasting spring- and summer-growth grain.There is no right or wrong way. It depends on the look you want.