by Chris A. Paschke, CPF GCF
The LA Framer – GLAC Newsletter March 2012
"The Versatile Offset Clip"
When a stretched canvas or cradled box is too deep for the selected frame…there's a problem, how exactly do you get it to stay in there? Offset clips are the very best way to hold paintings on rigid backings into picture frames, though artists have come up with many other solutions, including bent nails.
Canvas clips, or bar clips, are a popular choice for artists to hold canvases that stick out beyond the back of the frame. Though this commercial solution is far better than using a bent nail, it is still not very secure, and most definitely not the professional solution (photo 1). They are a simple, one piece spring steel clip designed to fit 1-1/2" to 1-3/4" stretcher bars, which are reusable, easy to install, and require no tools, adhesives or fasteners. Canvas clips wedge into the gap between the stretcher and the frame, and then by pressing down, the teeth pierce the inside edge of the frame rabbet. The opposite end of the clip snaps down to grab the inside of the stretcher bar to hold it in the frame. Though one clip per side is suggested by suppliers as adequate for installation, the corners of a larger canvas may warp out making this a much less secure mounting option. If you are selling framed canvases it is in your best interest—and that of your collector—to properly frame any original canvas prior to display and sale.
Commercial canvas clips
mounted in shallow wood rabbet
Stretched canvas in deep cap frame
held away from lip by 3/4" offset clip.
First comment, always select a frame that is deep enough for the stretched canvas. That said, not all artists or customers understand that theory and may be advocates of canvas clips. Time for a little consumer education.
This z-shaped hardware referred to as an offset, canvas offset, offset mounting clip, z-clip, or frame clip, is a zinc plated stair-step shape with rounded corners designed for use to affix various levels of stacked frames, liners or to install canvases when the depth of a picture frame is too shallow for points. The added beauty of an offset clip is the potential for holding the canvas away from contact to a wood frame—sealed or not—thus preventing the surface from rabbet lip damage (diagram 1). They are available 1/8", 1/4", 3/8", 1/2", 3/4", 1" and 1-1/4" as shown in photo 2, and come with and without holes in either end, though the holes are the best option. They are generally affixed with #6 pan or round head metal screws at a screw length long enough to hold soundly while not threading through the art board or frame.
Offset clips 1/8" to 1-1/4".
Offsets are also great for attaching cradled boxes (diagram 2) to floaters and are the logical alternative to screweyes, pan screws or staples. Screwing to the back of a float frame does leave the screw head projecting behind so selecting a longer offset attached horizontally prevents screw heads from touching the wall (diagram 3).
Cradled box in deep float frame
held with 1/4"-1/2" offset clip.
Screw head touches wall.
Cradled box in float frame
with 3/4" offset clip inside back.
At least four offset clips should be used per small painting, two across the top and two across the bottom. Placing additional clips at the center of each short side is a good idea and use more as the painting gets larger. Placement of offsets should be 8-10" apart around the perimeter. Though many clips come with two holes, the second hole is generally used when stacking picture frames or liners, but not necessarily for securing original art (photo 3).
Masonite original held
with 1/4" offset and 3M
A 1/4" offset clips the frame to the liner,
an 3/8" offset is used to mount the
painting with lifter to the frame unit.
Liners and Lifters
Liners may be added to frames and stacked mouldings may be joined using the offset clip method too. A recent frame repair brought in by a customer required 3/8" clips to be added to secure a linen covered wood liner into their shallow decorative frame. Then the original egg tempera painting on hardboard--which had been backed with a 1/2" x 1-1/2" pine lifter glued to the back of the panel—was fitted using 1/8" clips (photo 4), as each layer was too wide for their rabbets..
Copyright © Chris A Paschke, 2012
For additional information on framing basics visit http://www.DesignsInkArt.com/library.htm or email me at chris@DesignsInkArt.com. There is a special section in the library for all past IEA Framing Matters articles from Wax-On!
Chris Paschke, CPF GCF
785 Tucker Road, Suite G-183
Tehachapi, CA 93561