Flexible, Cardboard, or Straight Tack Strip: Which One Do You Need?

If you've started shopping for tack strip and landed on three different products — straight, flexible, and cardboard — you're not doing anything wrong. All three are real, and most upholstery projects actually use more than one. The short answer: straight metal tack strip is for crisp, visible edges, flexible tack strip is for curves, and cardboard tack strip is for seams you won't see. Which one you need depends on where on the piece you're working, not which one is "better."

By the end of this post you'll know exactly which tack strip to order for your project — and whether you need more than one type.

What Tack Strip Actually Does

Tack strip is a thin strip — metal or cardboard, depending on the type — lined with small spikes or nails along one edge. It grips upholstery fabric and holds it taut against the frame, giving you a sharp, straight finished edge without hand-tacking or a visible row of staples. It's what separates a store-bought-looking seam from one that looks stapled together at home.

Which type you use comes down to two questions: can the viewer see this seam when the piece is finished, and is the frame straight or curved there?

Straight Metal Tack Strip: For Crisp, Visible Edges

This is the one to reach for on the outside back or outside arm of a piece — anywhere the seam is straight and stays visible once the project is done. It creates a clean, thin edge without the look of staples showing through, and it works with both fabric and leather.

Straight Metal Tack Strip is sold in 14", 17", 24", and 30" lengths — measure the edge you're covering and trim the strip about 1/2" shorter, cutting off as few spikes as possible. Once it's in place (spikes facing out, aligned to the frame's edge), the fabric gets pulled onto the spikes, the strip rotates inward so only the spikes show, and a rubber mallet sets it flush. No staples on the visible side at all.

Flexible Metal Tack Strip: For Curved Frames

Straight tack strip can't follow a curve, which is exactly the problem flexible tack strip solves. Reach for it on wingbacks (chairs with tall, angled side panels), curved arms, or any arched section where a rigid strip would crack or leave gaps.

It's built differently, too — one edge has teeth, the other has holes, so it staples onto the frame first and then pinches closed around the fabric for the same seamless look as straight strip, just on a curve. Flexible Metal Tack Strip comes as a 20-foot roll rather than pre-cut lengths, since curved sections vary so much in size from one project to the next — one roll typically covers more than one curved seam.

Cardboard Tack Strip: For Hidden Seams and Piping

Cardboard tack strip solves a different problem entirely: it's not for edges anyone will see. Use it on the back of a chair, underneath the arms, or anywhere else the eye doesn't go — plus alongside piping (the thin, fabric-covered cord sewn along some upholstery seams for a finished look), where it keeps the piped edge from drooping or losing its shape over time.

The installation reflects that hidden purpose. Fabric gets draped face-down over the frame, Cardboard Tack Strip gets stapled on top of it close to the frame's edge, and then the fabric folds back over to completely conceal the strip underneath. Nothing about it is meant to show — you're stapling in a finished edge, not a visible one. (You may see "chip strip" used for this same product in some official diagrams — same part, just an alternate name that shows up here and there.)

How to Decide Which Tack Strip You Need

Walk the piece and match each seam to one of these:

• Seam is straight and stays visible when you're done → straight metal tack strip
• Seam is on a curve (wingback, rounded arm, arched back) → flexible metal tack strip
• Seam is hidden, or running alongside piping → cardboard tack strip

Most full reupholstery jobs use at least two of these — straight tack strip to finish the visible sides while cardboard tack strip closes up the back, for example. Don't assume one type has to do the whole project.

What You'll Need

• Straight Metal Tack Strip, Flexible Metal Tack Strip, and/or Cardboard Tack Strip — whichever match the seams on your piece
• Tape measure
• Tin snips (for cutting metal tack strips to length)
• Rubber mallet (for setting straight metal tack strip)
• Staple gun (for flexible and cardboard tack strip)
• Scissors (for cutting fabric and cardboard tack strip)

When to Call a Pro Instead

Tack strip work is beginner-friendly on a sound frame. The one exception: if the wood underneath is cracked, splitting, or crumbling as you try to staple or hammer into it, that's a frame problem, not a tack strip problem — and it's worth having a professional look at the frame itself before you put new fabric on top of it.

You Don't Need to Guess Anymore

Once you've matched each seam on your piece to the right tack strip, the actual installation is straightforward — no special skill beyond following the steps once with the right part already in hand. You'll end up with the same clean, professional edge a pro upholsterer would leave.

Ready to order? Shop tack strips and pick the type that matches your project.