Caulking is used for sealing gaps, most often for practical purposes: eliminating drafts around windows and doors, sealing tubs and sinks, and so on.

Painters generally use caulking for aesthetic reasons. Uncaulked gaps along the top of baseboards, in wood trim or along cabinets and countertops look unsightly and unprofessional.

Caulking can also be used to give straight, clean lines, like at the juncture between hardwood floors and painted baseboards, or where cabinets meet a wall.

Caulking tips

• Read the labels and buy the correct caulking for the job. When using caulking on the exterior of your home, be sure not to apply it in extreme temperatures or direct sunlight.
  

• Buy a good caulking gun that comes with a built-in cutting tool and wire attachment for piercing the tube's inner seal. Inferior caulking guns have a weak spring, which means that even after releasing the trigger, you will continue to ooze caulking material from the nozzle. This is really annoying and messy.
  

• Cut the tip at an angle and at the smallest opening you think you will need.
  

• Use a damp rag, usually followed by a wipe with your finger, to smooth out the bead of caulking. Do this right away, as it will start to skin over quickly and gets lumpy and hard to work with.
  

• Always leave ample time for the caulk to dry if you are going to paint over it, or it will shrink and crack the paint as it cures.
  

• To make a straight line where painted surfaces meet unpainted wood, like where cabinets meet a wall, or painted baseboard meets the floor, tape along the edge, leaving the smallest possible amount of wood showing--1/16 of an inch or so. Make the line as straight as possible. Run a bead of caulking along the tape edge and smooth it out right away, removing all excess caulking. Immediately and carefully remove the tape. When done properly, this fills unsightly gaps where the two surfaces meet and gives you a crisp, straight line. It looks very professional and clean.
  

• Caulking comes in many colors. Standard colors are gray, black, tan, brown, off white, clear and white. Some boutique paint and decorating stores carry a much wider array of colors, or you can find different caulk colors online.
  

• Push a nail into the end of the tube in between uses or for storage to prevent it drying out.