Quality is more than appearance

Made exclusively to fit Pac Trim® Top Quality Primed MDF Mouldings

CaliforniaInstallation TipsProduct LinePacFit Keystone Crown & Corner System

PacFit® is an innovative, miter free MDF moulding system designed to simplify installation by eliminating the need for precision miter cuts. PacFit® is matched to fit a selection of quality Pac Trim® profiles and can be utilized in new home, commercial, and remodel construction projects – small and large. Guaranteed to be the finest primed MDF product on today’s market, PacFit® is manufactured from the same top quality medium density fiberboard as Pac Trim®. Both are treated with PacPrime®, a unique coating that accepts any type of construction grade paint. PacFit® is durable, environmentally sound, and delivers ready to paint and simply nail into place. Visit the videos section of our website for details!


Installation Tips

  • Allow all moulding materials to acclimate to an indoor environment 48 hours prior to installation.
  • Make sure all surfaces are smooth and clean and all corners are 90 degrees.
  • Cut all materials before any nailing or gluing to ensure accuracy. Nailing supports are required for the back of the crown mouldings.
  • PacificMDF_SCS-MC-01171_FCP (Custom)Attach all PacFit® products to wall and ceiling using trim nails or construction adhesive.
  • Apply caulk to seams and light spackling compound to nail holes for best results.
  • Paint with any quality construction-industry paint. Be sure to read the paint manufacturer’s specific recommendations.


Crown Corners & Keystone

Installing crown moulding in your home has never been easier. PacFit Interior MDF corners are designed to fit perfectly over PacTrim’s PT#49 crown (available through many sources), but will also closely fit many 3-5/8″ width (#49) crown patterns sold at home improvement stores.

PTP-623 9/16" x 3-1/4"

Outside crown corner


Inside crown corner

PTP-356 5/8" x 2-1/4"


Radius Corners

Many modern home designs incorporate rounded corners that can create a challenge to fit baseboards and chair rail correctly. Radius corners provide the answer.

PTP-356 5/8" x 2-1/4"

PTP-356 5/8″ x 2-1/4″

PTP-612 5/8" x 6-1/2"

PTP-612 5/8″ x 6-1/2″

PTP-623 9/16" x 3-1/4"

PTP-623 9/16″ x 3-1/4″

PTP-218 9/16" x 5-1/4"

PTP-218 9/16″ x 5-1/4″

PTP-163E 9/16" x 5-1/4

PTP-163E 9/16″ x 5-1/4

Extensive Product Line Includes:

  • Outside Crown Corners
  • Inside Crown Corners
  • Rosettes
  • Keystones
  • Universal Corners
  • Plinth Blocks
  • Chair Rail
  • Radius Corners

Universal Corners

PacFit® Universal Corners can be cut to the desired height of the product selected to match the base.

#36 Outside Radius 1-1/8” x 1-1/8” x 8”

#36 Outside Radius 1-1/8” x 1-1/8” x 8”

#35 Outside Square 1-1/8” x 1-1/8” x 8”

#35 Outside Square 1-1/8” x 1-1/8” x 8”

#34 Inside Square 1-1/8” x 1-1/8” x 8”

#34 Inside Square 1-1/8” x 1-1/8” x 8”

Chair Rail

Typically installed 41” from the floor, chair rail blends well with modern and traditional architectural designs.

#31 Inside Square 1-1/8” x 1-1/8” x 5”

#31 Inside Square 1-1/8” x 1-1/8” x 5”

#32 Outside Square 1-1/8” x 1-1/8” x 5”

#32 Outside Square 1-1/8” x 1-1/8” x 5”

#33 Outside Radius 1-1/8” x 1-1/8” x 5”

#33 Outside Radius 1-1/8” x 1-1/8” x 5”

Simple, effortless installation ideal for the “do-it-yourselfer” and the seasoned, professional finisher.




  • Measure room and purchase PacFit® Keystone Crown & Corner materials.
  • IMPORTANT: Do not place directly onto concrete surfaces, use spacers to elevate from floor (trim will swell due to moisture absorbed from concrete).

REQUIRED TOOLS & MATERIALS: Tape Measure . Safety Goggles . Small Square . Hammer and Nail Set or Nail Gun . Saw . Electric Drill . Sandpaper . Nails . Wood Putty . Pencil . 2” Masking Tape . White Carpenter’s Glue (optional)


  • Make sure all surfaces are smooth and clean. Keystone crown corners will work on rounded or square corners.
  • Measure each wall from corner to corner making allowances for center gaps (refer to Fig. 1) and inside corner hold backs (refer to Fig. 2). Outside corners can be cut flush or slightly back from edge of corner.(refer to Fig. 3). Mark stud locations* and center point of each wall just below where bottom edge of crown will be installed.
  • Mark and cut crown to size.

*Use painters tape to mark walls for ease of removal later.


  • Attach crown to wall using a nail gun or by hand nailing** adjusting for predetermined gaps and holdbacks. Leave both ends loose to allow for movement when aligning keystone crown corner for installation.
  • OPTIONAL: When attaching, apply adhesive to back of crown corner, insert over both ends of lineal crown and nail in place.
  • Prepare for paint by removing any marking tape, caulk all seams and putty nail holes. Sanding will be required after putty dries.
  • Apply any quality construction-industry paint following manufacturers’ recommendations.

If hand nailing, pre-drill nail holes before installation using a drill bit one size smaller than diameter of the nail .