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This morning, I was preparing some images for an upcoming exhibit installation, and I had to cut some matboard.

My friend/teacher Sarah Thompson taught me pretty much everything I know about cutting matboard – and I expounded a bit on her system, as I am extraordinarily mathematically challenged (that’s no secret, by the way).

There are some good pre-cut mats out there, so you may never have to experience the full joy (being sarcastic) of this process – but, if you print random sizes (like I do) or want to crop a larger print (like I sometimes do), it’s worth learning how to do this yourself.

To mat a photograph, you will need the following supplies:

Illustration 1: some matting supplies

Illustration 1: some matting supplies

  • A photograph
  • Matboard (note: I usually use 4-ply to mat; 2-ply for backing board) + you’ll need an extra piece of 4-ply to use to back the piece you cut with the bevel cutter
  • A mat cutter (note: I use a Logan)
  • A straight cutter (sometimes)
  • A bevel cutter (all of  the time)
  • Archival quality linen tape (note: there is gummed and there is self-adhesive linen tape. There are pros and cons to both [whole other blog article]; I happen to prefer the self-adhesive variety)
  • A pencil
  • An eraser
  • A ruler
  • A T-square
  • A calculator
  • Some scrap paper for your calculations (unless you’re Rainman, or something – and I am NOT, which is why I require paper and plenty of it)
  • Ample workspace, something preferably at kitchen counter height (note: I use my dining room table…plenty of room, but it’s low, so my back pays the price if I mat a lot in one session)


Step 1:  Figure out how large your finished matboard will be.

Most times when I exhibit, I use 14″x18″ matboard, which is a standard size.

For today’s project, my final finished size was 14″x14″, so I measured and hacked 4″ off the five matboards I needed with the mat cutter and the straight cutter.


Step 2: Determine how large your image is.

Step 2: measure your image (horizontally)

Illustration 2: measure your image (horizontally)

If you print by hand, be sure to take several measurements from top to bottom (and from side to side). If you’re like me, the blades on your easel may not always be 100% even – and by measuring a few spots from top to bottom, you can determine the smallest width or height (skip this step, and you may end up with a big ol’ white border peeking out under the mat. Trust me. I’ve done it).

Step 2: measure photo (vertically)

Illustration 3: measure your image (vertically)

For this example, the overall image size was 4 11/16 (or 4.6875) inches square.

Set the photo aside for the time being. You’ve got a few things to do before you come back to it.


Step 3: Calculate the size opening you need – and also figure out if you want it completely centered (or not).

Rule of thumb: whether you’re cropping a larger image or not, you’re going to need the mat to overlap the image by about 1/4″ (or .125″ – sorry, not raised on metric…) on all sides (lest you see some white border…or parts of the image you don’t want to see anymore).

For this example:

  Image Width:  4.6875″ – .125″* = 4.5625″
  Image Height: 4.6875″ – .125″* = 4.5625″

      *=allowance to give me 1/4″ mat overlap

So: cutting a hole 4.5625″ x 4.5625″ would leave me with a hole small enough for the mat to cover the image edges sufficiently.

Since I was using a 14″ square frame for this project, I also wanted to make sure that hole was completely centered.

For this example:

    14″ (mat width) – 4.5625″ (the adjusted image size) = 9.4375″
       9.4375″/2 (to center – divide in half) = 4.71875″

   14″ (mat height) – 4.5625″ (the adjusted image size) = 9.4375″
       9.4375″/2 (to center – divide in half) = 4.71875″

4.71875″ = 4 3/16″

To perfectly center this image on the 14″ mat, I needed a square with lines 4 3/16″ off the edge of the mat.

If you are using rectangular mat and/or you don’t want the image completely centered on the vertical axis – a good rule of thumb is to let more mat fall under the image (e.g. keep it from looking “top heavy”).

Use the above width calculation to center the image horizontally, and then figure out how much “headroom” you want for your vertical axis.

I consistently frame my images 5″ from the top and adjust my bottom cut according to the adjusted height of the final image (remember: allowing for 1/4″  of mat on all sides to cover the edges).


Step 4: Draw the outline of the calculated opening.

Illustration 4: This is where the T-square comes in handy

Illustration 4: This is where the T-square comes in handy

First things first: make sure you’re drawing on the BACK of the matboard (again: been there, drawn on the wrong side PLENTY of times).

With the aid of the T-square, it’s easy to mark 4 3/16″ off the edge of the mat. Mark more than 3 points to ensure you’re plotting a straight line.

Repeat with the other three lines until a square is formed.


Step 5: Connect the dots.


As shown in the illustration: the square is centered, but the lines of the square extend beyond the actual square itself.

Illustration 5: Make sure your corners are visible

Illustration 5: Make sure your corners are visible

 That’s really important because the line extensions will ultimately guide you when you’re using the bevel cutter (again: something I learned. The hard way).

Note: we’re looking at the back of the matboard, so in the end, no one’s going to see your pencil lines (but, you have your handy dandy eraser, so you can erase ’til your heart’s content when the cuttin’s done).


Step 6: Get ready to make the first cut.

Illustration 7: Align your bevel cutter before you make a cut

Illustration 6: Align your bevel cutter before you make a cut

 So, at this point:

1. Your mat cutter has a piece of blank 4-ply matboard wedge underneath the guide bar

2. Your 4-ply matboard (with your shiny new penciled-in square) is lined up so that one pencil line is parallel to the guide bar.

3. Your bevel cutter’s center line (see the silver line on its edge) is aligned with the pencil line that is perpendicular to the guide bar.

Step 7: Cut!
Illustration 7: Lean on the guide bar, depress the blade and slowly push away from yourself

Illustration 7: Lean on the guide bar, depress the blade and slowly push away from yourself

OK. The Moment of Truth: Cutting.

I usually lean on the guide bar with my left hand – to make sure the two pieces of mat board don’t slide around while I cut.

I then push down on the bevel blade so it cuts into the first layer of matboard – and then somewhat slowly – but evenly – push the blade away from myself, aiming toward the next corner (ahh….now you see why it’s a good thing to have the corners well-delineated!).


Step 8: Stop! Don’t go too far!

Illustration 8: Stop when the cutter guide meets the penciled line

Illustration 8: Stop when the cutter guide meets the penciled line

The little silver line on the bevel cutter is your best friend. It will – like your other friends may or may not – let you know when you have gone.too.far.

When your BFF gets to the next perpendicular penciled line: STOP.

Don’t cut past your corner.

You’re good to go.

Now, just rotate the board 90 degrees counterclockwise – and repeat Steps 6-8 three times, until you’ve cut out your square.


Step 9: Pop out the center square.

Illustration 9: Square removed. Mission accomplished.

Illustration 9: Square removed. Mission accomplished.

This will happen effortlessly if

A) You pressed hard enough to cut through the mat entirely

B) You cut your corners cleanly

C) You weren’t using a raggy blade

It’s not easy going back over your work, trying to “even it up.” Best to do it right the first time. Trust me.


Step 10: Mount the photo

Illustration 10: Mount the photo with linen tape

Illustration 10: Mount the photo with linen tape

 There are different approaches to this.

1. If you are using a 2-ply backing board, hinge it to the backside of the cut 4-ply board so when closed (like a book), the nice freshly-cut beveled opening is all there for the world to see.

    Then: place your image on the 2-ply board (for positioning) and close the 4-ply hinged piece on top of it. Move the image around – as needed – to make sure there aren’t any edges or gaps or whatever showing (note: this is where those little Marcel Marceau-like cotton gloves come in handy, as they’ll keep your prints off your prints).

    Once the image is in place: use your linen tape to secure the image in place (or, if you want to be super-archival about it, make little corner pieces out of archival-quality paper and stick the corners of your image in them…and the tape doesn’t even have to touch your precious work).

2. If you don’t use backing board (I usually do, but today: I didn’t have to for the frames I was re-purposing), the easiest thing to do is run a length of the linen tape on the back of the top edge of your image.

     Flip it over, so the image – and the sticky side of the tape – are right-side up.

     Position the mat (nice side towards you) and when everything’s aligned – press down on the mat so the linen tape adheres.

     Flip over the image and secure the other sides.

That’s it!



To calculate an “adjusted” image size to include 1/4″ allowance:

Image Width = ______ – .125 = Final Image Width

Image Height = ______ – .125 = Final Image Height.


To center an image horizontally:

Mat Width ____- Adjusted Image Width ____=____/2 =_____ (to center)


To center an image vertically:

Mat Height ____- Adjusted Image Height ____= ____/2 + _____(to center)


Conversions (I can think of soda and wine in terms of liters, but that’s as metric as I get):

1/16 = .0625     5/16 = .3125     9/16 = .5625     13/16 = .8125
2/16 = .125       6/16 = .375       10/16 = .625     14/16 = .875
3/16 = .1875     7/16 = .4375    11/16 = .6875    15/16 = .9375
4/16 = .25         8/16 = .5           12/16= .75