Two of the Gallery’s largest and most treasured paintings require special attention from conservators to stay in the best possible condition. Here, Alex Forrest elaborates on the technical elements of the preparation and maintenance of these generously proportioned works.

At approximately two metres high and six metres wide, Mirdidingkingathi Juwarnda Sally Gabori’s Dibirdibi Country 2008 and the collectively painted Makarrki – King Alfred’s Country 2008, led by Birmuyingathi Maali Netta Loogatha, are two of the largest works on canvas in QAGOMA’s Collection. These significant paintings by the Kaiadilt artists are frequently requested for loan by national and international art museums, and due to their size, they usually travel unstretched — removed from their timber support and rolled for safe transportation. The QAGOMA Conservation Frames and Furniture Studio (CFFS) undertook the in-house manufacture of new stretchers, and this article documents the challenges, processes and results of this project.

Both works are painted on commercially primed linen canvases. Before painting, the canvas (known as the primary support) is laid across the stretcher (the auxiliary support) and held in tension with staples. Unlike a strainer, which has fixed corners and is not adjustable, a stretcher relies on a tight-fitting, expandable corner joinery called a full-mitred bridle joint. Timber wedges or ‘keys’ are inserted into the interior corners of the joint, enabling the joint to expand and apply the necessary tension to the canvas. Expandable stretchers have been used for paintings on canvas since the mid-eighteenth century. For the best long-term condition of a painting, stretchers are preferred to strainers and are recommended to artists.

Large paintings such as these present design and construction challenges. They require adequate cross-bracing (a wooden framework) between the stretcher bars to increase its overall rigidity, and to allow good canvas tension without distorting the stretcher bars. Additionally, all horizontal stretcher bar and bracing components must have an integrated joint in the centre, enabling the stretcher to be disassembled into two halves for transport. We investigated various joinery methods, including traditional Japanese joinery, but in this instance we resolved to use an aluminium angle solution, incorporating a mortise and tenon joint (which connects two pieces together end to end) for increased strength and to help with alignment during the stretchers’ assembly. The aluminium angle is recessed into the stretcher bar, so that the canvas wrapped around it can remain flush. The aluminium is attached to the stretcher bar using countersunk bolts into heavy-duty insert nuts, suitable for repeated use.