Believe it or not, there is an easier way to paint baseboards than to painstakingly cut them in with a small brush. Rather than spend hours slowly going over the baseboards, making sure not to slather any paint on them, you can paint the walls just above the baseboards in a manner that will guarantee a straight paint line and no paint on the wood. Once you learn the technique, you can apply to just about any surface that requires care so as to avoid running paint or unwanted splotches. No matter how many baseboards you have to paint around, the bulk of the job will be preparation. With that out of the way, the painting becomes the easy part.
Step 1: Prepare the Supplies
The first step is to gather everything you need for the job. It makes it a lot easier if everything is right in front of you. That way, you don't have to waste time gathering it after the fact. Have the paint mixed and ready to apply, clean brushes and all of the other supplies within an arm's reach.
Step 2: Masking Tape
To begin with this special painter's technique, pull off a length of masking tape long enough to work with but still within a manageable size. Let a few inches overlap where the baseboard meets the molding, and where the baseboard meets the wall, stick the tape to the baseboard in as straight a line as possible. It should be no more than a millimeter or two from the wall. Continue to stick the tape along the baseboard evenly and straightly. Continue like this until the entire baseboard top is covered.
Step 3: Painter's Caulk
Load up the caulking gun with the painter's caulk and prepare it for application. Where the edge of the masking tape meets the wall and holding the gun at an angle so the tip presses into where the baseboard meets the wall, run a small, even bead of caulk the entire length of the baseboard. If you have to, go over any spots you miss. It need not be very thick.
Step 4: Smooth with Finger
With your forefinger, smooth out the entire bead of caulk so it is compressed smoothly between the top edge of the tape and the wall.
Step 5: Paint
Now you can paint along the top edge of the baseboard, cutting in the wall without getting any paint on the baseboard. Be careful not to slather any paint so it runs over the bottom of the tape. The whole length of wall can be done like this in a minute or so. Don't worry about going higher than two inches or so above the baseboard. You'll get the rest of the wall with a roller.
Step 6: Remove Tape
After the cutting in is done, carefully pull off the strip of masking tape, pulling out and away from the wall as you do. You will be left with a perfectly straight edge of paint and not a drop to be found on the baseboard.
This is a great technique for painting around baseboards. Instead of trying to eyeball it and spending an hour going over a baseboard to avoid getting it wet with paint, use this trick and be done in minutes.