Everything You Need To Know About Stretcher Bars - Jackson's Art Blog (2023)

If you have decided to cover your canvas yourself, you need to choose your materials. The rods over which you stretch the canvas are just as important as the canvas in determining the end product. You may want narrow bars to make the painting easier to frame, or deep bars so it looks good unframed. If you are planning a very large screen, you should consider the stress that all that taut screen puts on the slats (your screen could warp), so heavier slats (thicker or aluminum) would be appropriate. Here are some things to consider when choosing your stretcher bars.

All stretcher bars differ from plain wood in that they are shaped to have a flat back and a sloping front that has a higher edge along the outside of each bar. This can be achieved with bars that slope down towards the center of the frame, or by adding a raised edging around the edge. The back is stapled flat and the canvas stretched so that it hovers over the sloping front, just touching the outer edge. This is to prevent paint goggles forming where the canvas touches the rod when the brush pushes the canvas towards the rod while painting.

Properties of each type

The Professional and Museum ranges are the bars used by most artists. The Alu-Pro range of bars is designed for artists looking to invest in the highest quality bars.
For very large sizes you will need to choose thicker bars for strength therefore the thinner bars are not available in the larger sizes.
"Depth" refers to the profile, the measure of how far the canvas protrudes from the wall when hung like a painting.
These poles can be bought in pairs to stretch your own canvas and are also used in oursfinished canvasesjcustom canvases.

Jackson's Professional Assortment

Wood in 3 depths - 18mm, 21mm, 43mm

• Strong, but for larger screens where canvas tension will be higher, the thicker 43mm bars are stronger than the narrower ones.
• The 18mm depth is available in inches, in 2 inch increments up to 40 inches. These 2" bars (and also the 21mm bars) are intended for artists who may need to adjust an inch-size frame or an existing inch-size painting where cm-size canvases are part fractions of an inch, or for those who prefer imperial measurements.
• The 21mm depth is available in inch sizes in 2 inch increments up to 54 inches. These two narrow wands don't come in as long lengths as the deeper wands as they aren't strong enough to last as long without warping.
• The depth of 43mm is available in increments of 10cm up to a length of 200cm.
• Strong interlocking corners and room for a wooden corner wedge.
• Made from PEFC certified kiln dried fir wood.

Die Jackson Museum Range

Wood in 2 depths - 20mm, 35mm

• Stronger with layers of laminated wood.
• Both depths are available in 5cm increments up to a length of 200cm.
• Strong interlocking corners and room for a wooden corner wedge.
• Constructed from layers of wood - PEFC certified kiln dried pine.

Jacksons Alu-Pro range

Wood and aluminum in 2 depths - 25mm, 45mm

• The strongest for aluminum.
• Both depths are available in 10cm increments up to a length of 200cm.
• The corners need connectors to join, which can be tightened like wooden wedges.
• Made of strong, lightweight aluminum with a wooden strip for stapling.
• Wood responds to changes in temperature and humidity, swelling when it gets hot or wet and shrinking when it gets cold or dry. Aluminum does not change its dimensions. This stability means that the canvas stretched over the bars is not subject to changes in tension and the paint layer does not have to be pushed and pulled, making it less likely to crack over time. The patented design creates a perfect frame for stretching the canvas, free from warping, twisting and sagging. These are so strong that any size crossbars are optional.

custom sizes

If you require a size that is not available as standard, Jackson's can cut all three types of stretcher. The order must be made by phone. The price is the price of the pole which is one size larger on our price list as your price list is reduced plus £10 per stretcher for the four new corner dovetails as these cut to size poles use a different binding. System.

Center Bar and Cross Bar: For added rigidity to prevent warping (and useful as a carry handle)

If the frame of a stretcher bar is very large, it's a good idea to give it extra support by adding a bar to the back (a center bar) or two bars to the back that cross each other (a cross bar). You can add a center pole for extra strength (and to have a handle on the back) of any size that has a slot in the pole to accommodate it.
You must use a center pole that fits over the support pole; Each bar size has a different size, so there are 7 core bar sizes/types.
If your support bar can only accommodate a center bar and not a cross bar, or if you just need the added strength of a single center bar, choose the bar that runs across, not the length. So a 50 x 100 cm canvas with a single center bar would have a 50 cm wide bar. This provides more stability than if the center bar were lengthwise.

For himProfessional 18mm and 21mmStretcher Bars The use of a center bar is recommended when each side of the canvas exceeds 30 inches. The canvas can only accommodate a center pole, it is not designed to use a cross pole. Sizes 28" and larger have slots in the center bar.

For him43mm ProfiTension frame The use of a center tension frame is recommended if one side of the banner is longer than 100 cm. Sizes from 80 cm have slits for the center bar. The 43mm bars can accommodate two crossbars that go on top of each other (in two planes) for extra strength.

IsMuseoThe 20mm bars accept a center bar or a pair of cross bars. Sizes from 50 cm have slits for the center bar. Centerpieces 100cm and over have a notch in the middle so two can be worn in a layer (on the same plane) as the notches match.
IsMuseoThe 35mm bars can accommodate a center bar or a pair of cross bars. Sizes from 60 cm have slits for the center bar. Centerpieces 100cm and over have a notch in the middle so two can be worn in a layer (on the same plane) as the notches match.

Museo Alu-ProThe bars accept a center bar or a pair of cross bars. These are referred to as primary cross members (in one piece plus required primary hardware connections) and secondary cross members (in two pieces plus required secondary hardware connections). They are only needed for very large sizes unless you plan to use them as grab handles.

Center pole length

Center sticks are smaller than extension sticks because they fit inside the rectangle, while extension sticks are sized based on the outside of the rectangle they create. But we've already figured out the appropriate sizes, and they're labeled with the size required for the rectangle, not the actual length of the bar. A 50 cm long center bar is not really 50 cm long, but fits into a 50 cm long stretcher bar.

corner wedges

Another name for the small triangular pieces of wood that come with the stretcher bars are keys.
New canvases often need to be tightened and old paints can loosen over time and need to be further tightened with corner wedges.
When stretching a canvas there is a gap in the wooden center poles to drive in smaller washers when the center pole needs to be tightened so there is a front and rear guide to the center pole to ensure the groove faces the back. .
Read more about wedges in this previous post:How to use the canvas wedges that come with a canvas or extension poles.

How to assemble the stretcher frame

Read about assembling our ranges of wooden shelving in this previous post:How to assemble canvas stretcher bars.

Read about the assembly of our Alu-pro stretcher frame series in this previous post:How to assemble canvas stretcher bars.

Stretching the canvas at Jackson's Art

These stretcher bars and everything you need to stretch artist canvases are available at jacksonsart.com. Stretcher bars can be selected on the user-friendly website and you can choose how to have them delivered to your studio.

• DIY Canvas Stretch - stretcher bars
• Stretching DIY canvases – canvases by the meter
• The canvas department

Postage is free for orders over £39 which ship to mainland UK addresses as standard.