One of the most frustrating parts of stretching a canvas print is trying to get the stretcher bars lined up perfectly to the edges of the image.
Nobody wants to see the border creeping around one side or another, or the composition of the image compromised by crooked stretching. Sometimes it’s really hard to tell where the image ends and the border should begin for a perfect canvas stretch.
Here’s a quick and easy trick to make stretching a breeze. We’ll be working with this image:
The first steps are in Photoshop. Determine what size the canvas needs to be in order to fit the stretcher frame, including about ½ inch per side to grip with the pliers. This little web sized painting is 12×12 inches. If we will use a 1 inch thick stretcher frame the canvas will have to be 14×14 inches plus another inch to accommodate the half inch per side needed for gripping with the pliers.
Step one, duplicate the Background .
Next, choose from the Main Menu Bar, Image/Canvas Size and increase the canvas from 12 to 15 inches square.
The image will now look like this:
Make a selection of the Background Copy (Command Click or Control Click on the image icon just right of the visibility eye on the Background Copy Layer).
Choose from the Main Menu Bar, Select/Save Selection and click OK. The selection will be saved as a New Channel.
Now, back in the Layers Window, use the Rectangular Marquee Tool to select the left side of the image on the Background Copy. Choose Layer/New/Layer Via Copy from the Main Menu Bar. (Command or Control J)
Notice there is a new layer above the Background Copy. With the new layer active, choose Edit/Transform/Flip Horizontal from the Main Menu Bar. Use the Move Tool to position the copied left side into position, nesting it up against the left side of the painting. It makes a mirrored view. Zoom in to make certain there is no space between the border and the image. The arrows on the keyboard may be used to move the piece pixel by pixel into perfect position.
Zoom out. Click on the Background Copy to make it the active layer and repeat the process on the right side of the image. If either side does not meet the outside edge of the new canvas, feel free to use Edit/Free Transform to stretch it to fit.
Use the Command or Control key to click on the Background Copy, and Layer 2 in order to have all three layers selected. (The shift key allows layers to be selected in consecutive order, the Command or Control key allows for selections not in consecutive order.)
Choose Layers/Merge Layer from the Main Menu Bar. (Command or Control E)
At this time, if you want to remove distractions, feel free to do so using Photoshop Tools, like Content Aware Fill, Clone Tool, Brush Tool, Patch Tool; whatever is appropriate to accomplish the objective.
Repeat the Rectangular Marquee Selections plus New Layer Via Copy for the top and bottom, this time choosing to Edit/Flip Vertical instead of Horizontal and positioning the pieces to mirror the top and bottom of the painting. Feel free again to remove anything that is obviously distracting.
After merging the top and bottom layers onto the Background Copy (it may not be named that at this point – just merge the top two layers onto the layer on top of the Canvas) the Layers Window will look something like this:
Make a New Layer. Layer/New Layer. The Layers Window will now look like this:
Now it’s time to mark the corners. Open the Channels Window. Hold down the Command or Control Key and click on the bottom channel, the one that was created when the selection was saved prior to creating the image border. Go back to the Layers Window. You should be looking at something like this:
Zoom in very close (don’t be shy) and choose the Brush Tool, a 1-3 pixel size at 100% opacity and a color that is different from those in the image. Make a small dot just inside the selection on each of the corners.
Deselect, flatten the image (Layers/Flatten) and Save. I usually choose Save As and give the file a name that lets me know what it is, for example, in this instance I might create the name 12x12_PrincessPainting_1B.TIFF to let me know that this is a 12×12 inch painting with a border for 1 inch stretcher bars = 15 inches square.
After the canvas has been printed and allowed to dry, give it a light protective coating of Breathing Color’s Timeless varnish.
While the coating is drying take a piece of scrap writing paper and scribble some graphite on it using a soft graphite pencil, like a 2B.
Lay the canvas face up on a flat hard surface, like a table. Place the paper under the canvas lining up the graphite under one of the marked corners. Position a small blunt object, like the tip of an unopened pen on the corner mark, press down and drag the graphite paper out from under the canvas. This will make a small mark of graphite on the back of the canvas exactly where the corner should be.
Repeat for the other three corners.
Now flip the canvas over. It will be easy to see where the corners of the stretcher bar should go. Line up the stretcher frame and put a staple center top and bottom, then staple from center to corner top and bottom, side and side. Finish the canvas with a heavier protective coat of Breathing Color’s Timeless varnish choosing a surface that compliments the values and contrast of the image.
It might seem like a lot of steps in Photoshop, but in practice it only takes a couple of minutes to size and mark the canvas for stretcher bar output and it makes finding those corners a breeze after printing! Once the corners have been tucked, the tiny dots from Photoshop will be all but invisible. Good luck and happy printing!
Jane Conner-ziser is an award winning photographer, digital artist, premier educator and independent consultant. With over 25 years of experience, 19 of them in digital imaging and evolving technologies, the techniques Jane developed for facial retouching and enhancement and portrait painting from photographs are widely emulated by photographers and digital artists worldwide through her classes, online training and educational products. You can learn more on her website.
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