Jackson's : Museum : Alu-Pro : 18x45mm : Primary Crossbar

Jackson's Museum Alu-Pro 18 x 45mm Primary Crossbars are made from aluminium, providing a strong, stable framework that helps maintain the overall rigidity of the stretcher, even as the canvas expands and contracts with changes in moisture. Your canvas would need to be over 120cm long on its longest side for you to need a Primary Crossbar for structural reasons. If your canvas is over 240cm on the longest side, you will require a Secondary Crossbar.

These Primary Crossbars have a depth of 18mm and are compatible with all Jackson’s Alu-Pro Aluminium Stretcher Bars. Designed to support the long sides of larger canvas frames, they add stability and can also serve as a convenient handhold during transport. If you are using just the one Primary Crossbar, you will want to be bracing between the two longer sides of your frame, so just make sure that you purchase a Crossbar which is the same length as the two shorter sides of your frame. Each crossbar features straight-cut ends and is sold individually.

Jackson’s Museum Alu-Pro Aluminium Stretcher Bars are quick and easy to assemble with a 4mm allen key and Alu-Pro Corner Connectors, and crossbars can be added at any time for additional support. For a frame that features a single 'Primary' Crossbar, you will need:

- A 4mm Allen key, preferably an Alu-Pro Allen Key
- Four Jackson's Alu-Pro Aluminium Stretcher Bars of whatever size you like
- Four Alu-Pro Corner Connectors (these are sold individually)
- Two Alu-Pro Support Connectors to fasten the Crossbar to the Stretcher Bars

For more information about Alu-Pro products and a series of assembly tutorials, see the Alu-Pro product showcase on the Jackson's Blog.