Getting the right fit starts with a few simple measurements. For half-round arches, the opening’s width is typically the arch’s diameter. For other arch shapes, measure the curve.

1. Measure width and height: Note the straight opening width and the rise of the arch.
2. Trace the curve: Use a flexible tape or make a paper/cardboard template.
3. Check product specs: Many arch mouldings list a diameter or radius range. Compare your measurements to those ranges.
4. Allow for trimming: Order a length that gives a little extra to fine-tune.

You can use Walmart’s filters to narrow by material and size, then review each product’s specification section for exact dimensions. Results can vary with unique openings, so dry-fit before final install.

Both types can elevate a space, but they suit different needs.

• Flexible moulding: Ideal for arches, curved walls, and non-standard shapes. It’s often foam, PVC, or rubber-based, sometimes peel-and-stick, and can bend to fit curves.
• Rigid moulding: Commonly wood or gypsum with crisp profiles. It’s great for straight runs like ceilings and baseboards and typically installed with nails, adhesive, or fasteners.

If you’re tackling a rounded doorway or uneven surfaces, flexible trim can simplify the job. For traditional crown or picture rails on straight walls, rigid options may offer a sharper look. Review each product’s material, length, and installation notes on the product page to match your project.

Peel-and-stick moulding can be a quick upgrade when applied carefully.

1. Prep the surface: Clean, dry, and smooth surfaces help adhesion. Remove dust and oils.
2. Plan and dry-fit: Mark a level line, position pieces without removing the backing to check fit.
3. Apply slowly: Peel backing a little at a time, press firmly as you go. A roller can help.
4. Avoid stretching: Keep the trim’s shape to prevent lifting.
5. Handle corners: Miter or use compatible corner trims where available.

For bathrooms or kitchens, consider waterproof materials and review the product’s usage notes. Adhesion can vary with texture and paint types, so testing a small area first is a helpful step.

Painting can be an option, but it depends on the material.

• Check the listing: Look for “paintable,” “primed,” or compatible paint types on the product page.
• Prep gently: Clean the surface and lightly scuff if recommended. Avoid harsh solvents on self-adhesive trims.
• Use the right primer: Wood often takes standard primers; some PVC/foam may need specialty primers.
• Test first: Try a small, hidden section to confirm adhesion and finish.
• Allow proper cure time: Follow paint and primer instructions for drying.

Not all mouldings are designed for painting, so following the manufacturer’s guidance usually leads to the best results.

Neat transitions come from planning and the right techniques.

• Inside/Outside corners: Miter cuts can create tight joints on straight runs. Some lines offer inside-corner trims that simplify installation.
• Curved doorways: Flexible casing or pre-curved arch mouldings can match the radius more easily. Dry-fit and adjust before securing.
• Consistent reveal: Keep a uniform gap around the doorway for a balanced look.
• Adhesive and fasteners: Use what’s recommended for the material. Press or clamp as directed.
• Final touch: Minimal caulk can help fill small seams before painting or finishing.

Check each product’s specs for length, profile, and compatible accessories to get smooth, cohesive transitions.