Splines are an effective and attractive way to add strength to a mitre joint.

The raw timber frame is cut with mitred corners, glued and allowed to dry under pressure with no pins or other hardware. Once the frame is solid, slots are cut perpendicular to the mitre and timber biscuits planed to the thickness of the slot are glued into place with the grain of the biscuit travelling across the mitre.

This crossing of the grain adds strength to the joint and creates an interesting effect where the end grain of the wood becomes visible.

Splines can match the material, can be contrasting in colour (sometimes still made using the same timber but lighter/darker), or they can be made using a different material altogether. Included here is an example of poloshed brass in maple.

We have developed our own swallow-tail splines that as well as preventing cracking from downward pressure on the mitre can help prevent the joint opening from outward pressure.