Building a simple picture frame from baseboard molding

Baseboard molding is an unlikely but effective material for a simple picture frame. A length of decorative timber gains a flat back that sits neatly against a drawing, print or photograph, while the moulded face supplies the detail normally provided by a factory frame. It works well for modest sizes, unusual artwork and a growing gallery wall.

In Australia, the same material is often called skirting, although shops also list it as decorative timber moulding. Bunnings and Mitre 10 commonly carry pine, MDF and painted timber in lengths sold by the metre, with dimensions given in millimetres. Ask the shop to square-cut the lengths if you plan to make the mitres yourself; buying one long piece for each pair of sides keeps the grain consistent.

Start with the visible artwork rather than the size of an offcut. A child's drawing, a school portrait or a small print needs only a little extra paper for handling, and every extra millimetre of timber reduces the opening. Measuring first prevents the common mistake of buying an attractive profile that cannot actually hold the picture.

Consider the room as well as the image. Restrained square timber suits a plain wall, while a stepped profile echoes traditional interiors without looking ornate. Decide whether the frame should disappear into the background or provide a clear border around the artwork, because that choice influences both the profile and the finish.

Choosing the trim and planning the frame

Baseboard trim comes in flat-backed, stepped, rounded and ogee shapes, but the squarer profiles are usually the easiest to cut cleanly. Pick something with a solid back, not deeply carved edges, for a first attempt. A narrow profile suits a portrait; a wider one gives a small print more visual weight.

Profiles worth considering

Use the finished opening to calculate the timber. For a 200 by 250 millimetre portrait and trim measuring 70 millimetres across its flat back, the outside frame will measure 340 by 390 millimetres. Each horizontal cut length then needs 480 millimetres, and each vertical piece 530 millimetres, including the two mitred ends.

Check the stock before cutting and subtract any damaged sections from your plan. If the timber has been stored in a garage or shed, let it acclimatise indoors overnight. Seasonal movement can twist a profile and pull a corner out of square while the glue sets.

Tools worth having nearby

Measuring and cutting the moulding

Mark the lengths on the flat back of the moulding with a sharp pencil, measuring every piece from the same reference edge. Use a speed square to mark a true 45-degree line, then tape over it to reduce tearing. A fine-tooth mitre blade gives a cleaner edge through the profiled face than a general-purpose blade.

Cut a test mitre on an offcut first. It should show an even 45-degree end with no gap or split at the widest point. Make the remaining cuts with the stock fully supported, then pair the two long pieces and check their fit before shortening anything. A slight error is easier to correct at this stage.

Once all four pieces are cut, arrange them around the artwork and mark the mitres directly on the back. The corners should meet in one continuous line, with the back edges flush. If the opening is tight, check the measurements again rather than forcing the frame around the paper.

Option Main advantages Main limitations Best suited to
Baseboard molding Decorative profile and economical offcuts Requires accurate mitres and careful joining A handmade frame with character
Flat timber strip Simple to measure and assemble Offers little edge detail A clean, understated gallery wall
Ready-made frame Consistent fit and convenient hanging Fixed sizes and limited customisation Projects where speed matters most

Joining the corners into a square

Apply a thin, even bead of PVA wood glue to one mitred end and bring the two pieces together. Bind the joint with masking tape, keeping the tape on the back where it will not show. The decorated faces should meet without a dark line, and the flat backs should sit on the same plane.

A small brad pin through the back of each joint can hold the alignment while the glue sets. Keep the fixing close to the mitre and away from the visible profile, and check that the pinned corners can still open slightly. For delicate or thin moulding, a mitre clamp can hold the joint without leaving pressure marks.

Measure both diagonals once the tape is removed. If they differ, the frame is a parallelogram rather than a rectangle, so gently correct the longer diagonal before the glue becomes firm. Wipe away squeezed glue with a damp cloth, then leave the frame undisturbed on a flat surface overnight.

Preparing the trim and choosing a finish

After the corners are secure, fill any small nail holes and gaps with timber filler, allow it to dry and sand the repairs flush. Use 180-grit paper on the flat back and 220-grit on the front, following the profile instead of sanding across it. A vacuum with a brush attachment keeps dust out of the deeper grooves.

For a painted finish, seal the end grain and any bare timber with primer, then apply two thin coats of water-based trim paint. Allow each coat to dry as directed, and lay the frame face down on a clean sheet so the profile does not pick up grit. MDF needs the same careful priming as timber.

Natural timber offers warmth but shows dents and grain more readily, so sealing and waxing are worthwhile for a frame that will be handled often. Matte finishes suit contemporary rooms, while gloss catches highlights on ornate profiles. Test the colour on an offcut, since the raised edges can look lighter than the flat sections.

A coordinated display can extend beyond the wall, and a guide to making a bead strand shows how simple craft materials can create a colourful personal accent. Matching the frame finish to such a piece gives a small handmade project a deliberate place in the room.

Adding the backing and hanging the frame

Most baseboard profiles do not include a recessed rebate for artwork. Make one with narrow timber offcuts fixed around the inner rear edge, leaving a shallow step of about three millimetres. Position the picture against that step, then cut clear acrylic to extend five to ten millimetres beyond the visible opening. This holds the paper without trapping it against the glazing.

Cut a three-millimetre hardboard panel to the outside size of the frame and paint both faces and the edges black to prevent shadows or pale timber marks showing through the paper. Fix the backing to the rear with small screws, keeping the heads away from the artwork. Screw a picture hanger or a pair of D-rings into the top rail, spacing them to balance the weight.

Wall fixing matters in Australia because construction varies from Sydney terraces with rendered or brick walls to timber-framed Melbourne homes and Brisbane houses with brick veneer. Use a stud detector, then choose masonry or hollow-wall anchors suited to the wall. Plasterboard on its own will not carry a heavy frame, so spread the weight across suitable anchors.

Keep the finished frame away from direct sunlight, heaters and strong moisture. UV-filtering acrylic helps limit fading, while a small gap between the artwork and the glazing reduces trapped condensation in humid weather. Hang it at a comfortable viewing height, check the fixings after settling, and the frame will remain secure and presentable for years.