The Perfect Cut-In – DIY

This article provides you with the information you need to paint a perfect cut in. We use this method when cutting into trim or other smooth surfaces (but use another method when cutting in up to the ceiling).

Tools/Materials Needed:

  1. Drop Cloth
  2. Blue Tape
  3. Caulk Gun
  4. Clear Caulking (We buy 950A Clear from Sherwin Williams)
  5. Paint Brush
  6. Can Opener
  7. Dry Rag
  8. Damp Rag
  9. Paint
  10. Stir Stick

Step by Step –

  1. First lay down your drop cloth down where you will be working.
  • Keep your tools/materials nearby.
  • Use a bigger drop cloth than you think you need (just in case).
  1. Wipe off the trim that you will be taping using a dry rag. It is important to clean off any dust or dirt.
  2. Using the blue tape, mask a perfectly straight line against the trim where you want to do your cut in, from end to end.
  • Always use long pieces of tape (we generally rip three to four foot pieces).
  • Press firmly at the top (or one end) and pull your tape tight, holding the tape close the edge you want to cut in. Your main hand should be holding the bottom of the tape taught, while your offhand is pressing the tape to the top (or first end).
  • Once the top (or first end) is secure, slowly work your off hand along the tape, attaching it to the trim. At the same time, keep your right hand holding the other side (bottom) such that the tape remains taught. Your right hand will move the tape around to ensure the line is straight.
  1. Inspect your masking to make sure the line is straight. If it isn’t, take your tape off and retry.
  2. Once the line is straight, make sure the tape is very secure by pushing your fingers along the edges.
  3. Take your tube of clear caulk and cut off as little as possible of the tip so that the hole where the caulk will exit is very small.
  4. Insert clear caulk into your caulk gun.
  5. Insert a teeny tiny bead of clear caulk along the edge of your tape, where your line is.
  • Do this by gently squeezing the trigger and pushing the tip of the tube along the edge simultaneously.
  • Hold the gun perpendicular to where you are caulking or angle it so that you are pushing the tip away from you as you squeeze the trigger. This will help prevent you from applying too much caulk (the tip on the tube acts as a scraper).
  1. Using your pointer or pinky finger, remove all of the clear caulk from the seam that you possibly can, scrape over the seam multiple times, wiping your dirty fingers on the damp rag. Leave no more than 1/16 of an inch of clear caulk. The caulk helps prevent the paint bleeding through the tape.
  2. Then dip your brush 1-1.5” into the paint.
  3. Apply a very heavy coat of paint directly to the caulked edge of the tape, continue to re-dip and re-apply every 6 inches or so.
  4. Once you have applied a heavy coat of paint over the edge of the tape and spread the paint out evenly, remove the tape.
  5. If done correctly, you are now looking at your super straight, crisp looking cut-in.
  6. Carefully use your damp rag to wipe off any paint that bled through the tape. (But don’t touch your new cut-in!)
  7. If it didn’t come out perfectly due to crooked taping or too much/too little clear caulk application – that’s okay. Just notice what wasn’t right and get a little better on the next one.