How to Choose the Right Stretcher

Which profile? How much cross bracing?

 

Considerations are to have the right profile and cross bracing for ease of use and stability of the frame during canvas stretching, and priming or other preparation of the painting surface, and for long term protection of the painting.

 

UCS has eight profiles (width and thickness of bars) to cover most needs. We can make any other required as a special order.

 

The cross bracing design and choice of profile depends on the size of frame, and on what is being stretched (whether a finished painting, or pre-primed, or raw canvas to be gessoed).

 

Cross bracing is used to support the longer bars, to keep them from bending in towards the center under tension from the stretched canvas. It is also required to keep outward pressure on the narrow ends of the frame, to prevent inward bending of these bars, which would cause the long cross braces to bow outwards at the back.

 

Proper cross bracing allows the frame to use the lightest possible bars and still be strong and stable under tension.

 

Many professional artists and conservators like to include at least one cross brace on any frame with bar lengths over about 24” just to protect the back of the painting from being accidentally hit during transportation or while in storage.

 

Assess the likely tension
To decide on the correct profile and cross bracing, first one needs to assess the maximum tension the frame may be under at any point in its life.

 

Tension on the bars comes from several sources:

  • The initial stretching pressure applied by the canvas pliers as one is stretching the canvas before tacking or stapling. NOTE: This does not have to be great. Reasonably tight is good enough. Any slight looseness can be taken up by tapping in the keys a bit after the canvas is completely stretched and stapled in place.
  • The weight of the canvas and paint layers, which is much greater for large canvases.
  • Raw canvas, wet with gesso, shrinks and puts a VERY LARGE strain on the bars and staples (and hence on the canvas itself where it is stapled). This is by far the most amount of strain a frame will ever have to bear, unless it gets wet again somewhere in its life.
  • Pre-primed canvas, and pre-painted canvas, puts much less stress on the frame, hence needs less cross bracing than raw canvas.

Note: raw linen, wet with gesso or glue sizing, can create more tension than the same size of raw canvas.

 

Design recommendations.
The design recommendations for the following six different profiles assume the maximum tension (raw canvas to be gessoed).

 

BASIC Stretcher Bar (1 5/8” x 13/16”):
Custom and stock sizes ideal for smaller canvas sizes requiring no cross bracing. Cross Bracing: one centered brace recommended on bars over 40”
Usual Size Range: 6” to 36”
Maximum Length: 48 inches for custom made bars
Minimum Length: 6 inches for custom made bars
more information on the Basic Bar profile

 



STANDARD Stretcher Bar (3” x 13/16”):
A strong and economical stretcher bar profile ideal for professional works which are not too heavy.
Cross Bracing: 25” centres starting at bar lengths of 40”.
Usual Size Range: 24” to 72”
Maximum Length: 8 feet for custom made frames
Minimum Length: 8 inches
more information on the Standard Bar profile

 



PROFESSIONAL Stretcher Bar (2 1/2” x 1 1/8”):
Our most popular stretcher bar profile with professional artists and conservators. It provides solid structural support in a keyable wood system without excessive bulk or weight. 3/16” rebate on the back side allows for a protective backing. Cross Bracing: 30” centres starting at bar lengths of 45”.
Usual Size Range: 18” to 96”
Maximum Length: 9 feet for custom made frames
Minimum Length: 8 inches for custom frames
more information on the Professional Bar profile

 



HEAVY DUTY BASIC Stretcher Bar (1 5/8” x 1 5/8”):
The Heavy Duty Basic stretcher bar is ideal for shorter frame sizes (60” and under) where extra thickness ‘off the wall’ or ‘gallery wrap’ is wanted. This stretcher profile is frequently used for the stretching of giclee and other prints.
Cross Bracing: 30” centres starting at bar lengths of 45”
Usual size range: 18” to 48”
Maximum Length: 5 feet for custom made frames
Minimum Length: 6 inches for custom frames
more information on the HD Basic Bar profile

 



HEAVY DUTY STANDARD Stretcher Bar (3” x 13/16”):
The Heavy Duty Standard stretcher bar is our most popular ‘large frame’ profile providing both great strength and stability combined with reasonable pricing.
Cross Bracing: 40” centres starting at bar lengths of 60”
Usual size range: 72” to 120”
Maximum Length: no maximum
Minimum Length: 12 inches for custom frames
more information on the HD Standard Bar profile

 



HEAVY DUTY PROFESSIONAL Stretcher Bar (2 1/2” x 2 1/4”):
The Heavy Duty Professional stretcher bar is extra thick (2 1/4” vs 1 5/8”) and therefore the strongest and most rigid. This profile is recommended for very large frames over 16 feet in length. This profile is also ideal for smaller frame applications where very high tension is required.
Cross Bracing: 40” centres starting at bar lengths of 60”
Usual Size Range: 108” to 144”
Maximum Length: no maximum
Minimum Length: 12 inches for custom frames
more information on the HD Professional Bar profile