How to Build a Pergola Style Upholstered Cornice

  My client had a number of oriental style accents and need new window treatments.  I suggested a pergola style cornice, showed her two sketches, she chose the one she liked best and I got started. <br>

She chose the bottom design which featured a stripe fabric in the center and on each end.  The end stripes would then line up with the stripe trim on the standing


A paper pattern was drawn.   Always remember to fold your pattern in half and trim again so both sides are the same.   Sing a felt tipped pen the pattern was traced on to 1/2" plyboard.<br>

Since the window was wider than the 8 foot length

plyboard comes in,  a piece had to be cut and spliced on one end.   It was secured with a 4" piece of plyboard glued and screwed.  The splice was used on the inside of the cornice so that it would not show.

A grid pattern was marked and cut out of the plyboard to lessen the weight but maintain stability.<br>

Side pieces were cut and aligned with the straight part of the cornice front, glued and screwed.  The board forming the top of the cornice was attached to the face and end boards forming the cornice "box." <br>

Two small end pieces were cut to align with the face board and were attached to the end boards of the cornice box.   A piece was attached to brace face board with the shaped end pieces.<br>

Here you see the final wooden frame of the cornice board.<br>

Black out lining is stapled over the geometric cut outs.  This is important to prevent the cut outs from showing through to the face of the cornice.<br>

Next the entire board is covered in heavy flannel inner lining.

Note that the flannel is stretched and stapled to the underneath part of the rounded portion on each end.<br>

Next fiber batting was spot tacked on the entire cornice board.

The Stripe pattern was cut apart and and stitched in place with the white fabric.

The cover was then stretched and stapled over

The cornice board.  *My earlier cornice blogs go into detail as to how to maneuver around corners and shapes.<br>

After the face fabric in stapled in place and trimmed, cut a piece of fabric a couple of inches wider than the depth of the cornice.

Lay it face down on the front of the cornice and staple the edge in place .

Then staple  cardboard stripping over the edge of the fabric just attached.  Be sure to align the top edge of the striping with the hard edge of the face of the cornice board.<br>

After the stripping is in place pull the fabric to the back and staple on the back.

Cut a 3" strip of fabric and repeat the process on the bottom edge of the front of the cornice board.

Line the inside with lining fabric.


Unfortunately the lighting in the house was so bad where it was installed I couldn't get a picture of the finished, installed window treatment.  It looked exactly like the original sketch.

Bill Gantt

How To Mitre Stripes

Original stripe of Three colors of silk and velvet mitred

I love to work with stripes!   Mixed with other patterns and solids , they are a great way to create interest and detail into a room design.   I use them to make interesting trims or accents on drapes  pillows and table cloths.

Pattern after first fold

How to mitre a stripe

Cut a piece of lining a few inches larger than you want the finished product.

Fold the fabric diagonally-corner to corner.  Press it with an iron.


Fold the piece diagonally again-opposite corners to corner-Press.

Pattern after second fold and lined up for cut

You will have a triangle shape about 1/4 the size of the original piece.  This is your pattern.

Place your triangle pattern on the striped fabric.  Make sure the

bottom of your pattern is aligned with the bottom stripe.   Also

It is a good idea to position the pattern so that the top point of

the triangle is over a large stripe.  This will make it easier to get

a neat square when you sew the 4 pieces together.

Cut your first triangle shape with the folded white lining pattern.

Two pieces sewn together

Then use the first striped triangle shape you cut as the pattern

for the next 3.   This helps assure that all four pieces will be

exactly alike.

Seam together two triangles, then seam together the other two.

Press the seams flat.

These pieces need to be turned face to face before being sewn

Place one set of sewn together triangles face up.  Put the other

set on top with the face down.   Be careful to perfectly align

the center seams.   Pin together.

Starting at the middle seam sew toward the outside point .

Then starting at the middle seam again sew to the other outside point.

Stripe trim being cut

Often I make a trim by cutting a stripe from a fabric.

It is much easier to mitre the entire pillow than to just try to sew the trim on and mitre the corners.

Many times the grain of even a solid fabric can give an interesting subtle effect when mitred.

Velvet triangles cut for two pillow faces

On these pillows the fabric is velvet which has a nap.  If done properly the differing directions of the nap when mitred will give a nice subdues effect.

To save on waste I have cut the triangles two directions.  With the velvet I must use all the triangles with the point up as cut for one pillow and the other, point down triangles for the second pillow.

Trim being applied to solid velvet

Measure an sew the trim stripe on each triangle at the same place.

Solid velvet and velvet stripe - red for covered  button

Finished pillow

As my pictures show you can even mitre a plaid.  I have mitred pillows using floral prints.   You can

even use the same technique on round pillows.   Just cut the lining a few inches larger than you want

the finished circle.  Fold the circle in half-press, fold it in half again-press.   Repeat the process

until you have the size triangles you want.  A round looks best with 6 or 8.

Mitred trim frames dog prints

Mitred dining room chair seat

"Explosion" pillow and small mitred pillow

Another type of mitre I have done is when a stripe is used to trim the outside edge of a pillow or table cloth.  If the stripe is used parallel to the edge of the item the methods described earlier work.

If however, the stripe is to be applied perpendicular to the edge of the fabric another issue arises

Fabric on the right is being aligned to be mitred


With a smaller multicolor stripe like shown here you will be able to mitre 3 corners at the same point in pattern and one mitre that will be at a different point.  With a stripe like this it is not so noticeable as with a bold 2 or 3color stripe.

For a project like this cut the large center piece of fabric and add a welt or trim on the edge.

Cut your stripes to the desired width.  To save fabric I usually join them all together end to end being extremely particular about the match so the seam is almost invisible

For this method, cut the strip of trim fabric the length of the center piece and add double the width of the trim fabric plus a few inches.  For example if the stripe trim fabric is 5" wide, add about 12" to your first cut.  With the trim fabric on the bottom facing up and the center fabric on top facing down, sew on top of the seam of the center piece trim seam.

Because this stripe is not balanced-one side is different than the other(see the cream colored grosgrain stripe next to the blue stripe) the next strip must be turned upside down to get a mitre.

Fabric trim is mitred and pressed 

Although I don't show it on the picture I recommend once you determine the edge that will be sewn to the center piece, you press over 1/2" along the top.  That is where you will be sewing.  Now put it next to the last corner and turn under one side to a 45 degree angle. If the edge of the trim stripe is perpendicular to the stripe showing on the upturned wrong side, it is 45 degrees.  Do the same with the piece you are adding. When they are perfectly aligned press a crease into both pieces.

Creased angles being sewn together

Now carefully fold the entire pillow face on the diagonal.  Noting the pattern, pin the two pieces of trim fabric face to face.  Be certain  that the angled creases you pressed in are one on top of the other.

Starting from the

outside edge

 sew the creases together with a medium stitch.  Be sure to lock the stitch on the outside edge.  nSew toward the center piece of the pillow or cloth.  When you reach the center piece trim keep as close to the corner as you can. Lock your stitch.

It is most likely that you may have to pick one or two out and redo them.  All the years I have been doing this I usually have one or so that I have to do twice until I'm satisfied.

underside of a successful mitre.

When the first corner is done to your satisfaction sew that strip up to the next corner.

Turn the fabric upside down(for this kind of stripe).  And find the point in pattern that will match the stripe at the top corner.  Turn the sewn piece so it is at a 45 degree angle(check to see if the face stripe is perpendicular to the stripe showing on the wrong side).  Pin it to your table.  Now do the same to the strip you are going to attach.  When the match is good press to mark and sew.

Last corner on the right. the part of the stripe to be eliminated in the middle

When you get to the last corner you no longer have the ability to shift the trim strip for a match.  With a mulit color smaller stripe, you find the pattern match on the corner.  Pulling as much fabric into that section as you need to match the first strip.  Press it into place and pin.  Now look at the excess fabric in the last trim strip and find a place where the pattern can be cut and joined will not be noticeable. For example on this one I paid attention to the location of the green and blue stripes.  The piece sticking up in the middle is where the fabric is coming out.

Once you find the place lay the fabric one direction and press in a crease then lay it the other direction and press in a crease.Be sure the fabric is always touching when your do the pressing.  Turn the fabric strip face to face.  With the center crease in the middle, line up and pin the other two creases together.  Lock your stitches and sew the two together.  Do not cut the excess off until you are certain everything lines up. Sew the upper edge of the last strip to the center piece and sew your last mitre in the corner.  All four corners are mitred and look great.

Bold stripe trim pieces laid out and checked with a framing square

If the finished size necessary for the piece is flexible, another approach that will get

all 4 corners mitred the same

, is to mitre the outside trim first and then attach the center piece when that is done.  With a bold or two color stripe this can often be the only way.  Unlike the stripe I showed you in the earlier example, stripes like these make eliminating part of the stripe on the last piece to get the mitre impossible.  Also with such a bold pattern you are much more likely to be annoyed with one corner having a different part of the pattern in the  mitre.

Trim strips adjusted to make a rectangular pillow

Because you must do a bold stripe this way you are only able to adjust the size of the pillow by the width of the stripe or by the repeat.

This stripe has a 9" repeat, so you can have a 27" by 27" square pillow or a 27"by 18" rectangle pillow.

  You are only limited by your creativity.

Good luck and please tell your friends about my blog.

Bill Gantt