INSTALLING FLEXIBLE TACKING STRIP from W. Lloyd Gheen's book
FURNITURE UPHOLSTERY TECHNIQUES ILLUSTRATED

Used by permission of McGraw-Hill Publishers

Flexible tacking strip (brand names Curve-Ease and Pli-Grip) finds it's specialty application anywhere curved surfaces are involved and visible tacks are undesirable. Two prongs are visible, these will grip the fabric as they are pressed toward the frame. The other tab has a hole punched in it through which a tack or one leg of a staple will pass, attaching it to the frame.
How to install furniture tack strips.
Locate the flexible tacking strip about 1/16" from the edge to be finished.
Cut with tin snips.
Continue attaching the strip to within 2" of the point it is to terminate and cut it to length with a pair of tin snips.
flexible tack strip
Tacking strip applied to the outside arm of a recliner.
Align, mark and trim the panel. Push all the pronged tabs of the tacking strip about half closed so they are at about a 45-degree angle. Lay the OA panel over the area and pin or stay-tack in place so it will not move during marking.
mark contour
The best way to mark the contour is to rub the side of the chalk along the edge of the metal.
chalk line
Trimming OA panel to contour, 3/8" beyond chalk mark.
Push fabric over teeth.
Relocate the fabric over the flexible tack strip, making sure the marked line exactly matches the contour of the tacking-strip edges.
Hook the fabric onto the toothed segments, pressing the fabric around with the fingers. A skewer is a handy helper to move the fabric around accurately. Keep the panel taunt during the tucking-under process.
press tabs down
Press the gripping tabs over against the frame. Fabric slippage can be prevented by pressing toward the tacking strip just inside the metal edge with one hand while pressing the nearby tabs with the other thumb.
white rubber mallet
Seat the tabs firmly against the frame. One handy way to do this is to use a piece of closed-grained hardwood to tap the tabs into place. Or better yet with a white rubber mallet.
stretch panel fabric
Stretch the bottom and ends of the panel as necessary and staple into place.

Sorry, this book now out of print.