Introduction: Cheap and Easy Fabric Covered Window Cornice

Hiya!  It's been a while since I've had the time to cruise around on one of my favorite show-and-tell sites and to write up all the 'ibles I've been taking pics for this last year.  Whew!  So glad to have some down time and so glad to be back.

This Instructable will teach you the very basics of making a window cornice box designed to hide cheap curtain hardware.  Window cornices have gone in and out of fashion throughout history.  They were traditionally made of wood and molding, though the more modern twentieth century incarnations were fabric covered.  This 'ible sacrifices sturdiness and longevity for cheap drama but the basics of how to make these lightweight fabric window cornices translates pretty directly to a more high-end wood version with a slight upgrade in tools and know-how. 

It was my mother who made upholstered cornice boxes for me many moons ago and I have to credit her for teaching me how to stretch my dollar into a lot of drama.  Ya... she airbrushed my room into a castle once.  And painted black and white checkerboard on my walls another time.  Even if her room was never finished, she always made sure my room had style.  I never realized how important that was to me until I became an adult and an artist.  I grew up watching decorating shows with her and holding the end of a sheet of plywood while she jigged something out.  She taught herself upholstery and reupholstered a sleeper sofa--a feat that gave me the confidence to rip my own sofa apart some fifteen years later ('Ible coming soon!).  She is an inventor, a builder, a designer, an entrepreneur, a scientist, and a terrible cook.  Even though we ate a lot of Burger King growing up, it was a totally great trade off for the skills she taught me.  Because of her, I'm not afraid to whip out my sewing machine and tools and make a mess, give something a try, go hog wild, make a change, add some color, and clean it all up later.  We have totally different design styles today, but she taught me how to make my environment come alive with a little ingenuity.  Thanks, mominator.  You made this Gryffindor common room possible.  ;-D


If, like me, you live in a rental, move a lot, are on a tight budget, are a college student/actor/artist/etc and yet can't NOT adorn your environment, this Instructable is perfect for you.  No heavy hardware or tools are required, takes about 2 hours, and you can probably make these for $30 or so, depending of course on what you keep in your storehouse.

You will need:
foam core -- number of sheets and size dependent upon your window size/qty
fabric -- like the foamcore board, this will depend on size and quantity
spray glue--I used Aleene's--it's great
hot glue and hot glue gun
Elmers glue (optional--this can all be done with hot glue if you prefer)
toothpicks (optional--you might want these if you use Elmers)
ruler -- I find a grid ruler works best.  If you're a DIYer and you don't have one (even if you don't quilt), you should invest in one.
fabric scissors
Exacto-style knife
tape measure -- if handy; if not, a ruler may suffice
drill or screwdriver
"L" brackets

1.  Measure you windows.  Technically, measure how much height, width, and depth you want your cornice boxes.  I opted for a 10 inch high box knowing I would do some kind of bottom design.  I also wanted them 4 inches deep because I have some quilted roman shades I hang in the winter to preserve heat.  Finally, I made them about 7 inches wider than my actual window just because.  
*A note about the boxes--you are technically covering ugly hardware BUT the drama comes when you 'fake out' the people invited into your living room.  Go taller and wider than your window and hang them higher than your hardware so that it gives the illusion of having bigger windows than you actually have. 

2.  Sketch out your design on foam core.  Once you have your desired dimensions, make your pattern on the foam core board.  This could be a plain ol' rectangle if you're going modern, or you can do a widow's peak looking swag-thing like I did.  The more detail you put onto your boxes, however, the more difficult it will be to cover it gracefully with your fabric.

3.  Using your Exacto knife, cut out your design.  Cut out the front, sides, and top.  Remember to measure twice, cut once.  Also remember that you need to account for your foam core's thickness in creating the top piece.  This means that for me, I cut 4 inch side pieces so my actual depth from the wall ended up being 4 1/8 inches by the time I added the front piece to the depth.

4.  Glue it all together! I recommend Elmers glue and toothpicks to start.  Simply run a bead along the edges you are putting together and hold in place by shoving some toothpicks from the front into the foamy side.  You could hot glue this if you wanted but I find hot glue is tough and melts the foam core.  Also, part of the charm of lightweight cornice boxes is that the fabric will help hold it together once all is said and done.

5.  After the glue is dry, trim your toothpicks and spray with tacky spray adhesive.I trimmed my toothpicks down and then shoved the remaining tiny point into the foam core with my fingernail so that the picks were flush.  Then, I sprayed the front and sides with tacky glue.  You can spray the top, too, at this point.  I didn't cut my fabric wide enough to cover the entire top since it won't be seen.  (If you're a theatre person, you know this as "it'll never read").
**Aleene's is tacky as all f**k so absolutely be sure to do this outside in an area that won't get sticky from overspray.  Also, don't coat the inside of your board unless you want to collect all manner of dust or bugs from any bits not covered in fabric.  You have been warned. 

6.  Adhere your fabric.  To do this, put your fabric right side down and place the tacky front of your board on the wrong side of the fabric.  Flip your cornice over and smooth out any lumps.  Starting from the front, wrap along the sides and, if applicable, the top.  If you are wrapping the top at this stage, be sure to make nice mitred corners in your fabric so it lays nicely.

7.  Trim to fit and clip your curves and corners.  Now that your cornice surface is covered, trim any bits away that are excessive.  For me, this meant trimming the rounded bits down so that there was about 1.5 inches of fabric overhang.  Then, every inch or so, cut to within about 1/4 of the board.  If you don't have round bits or curves and are making a perfectly rectangular cornice box, you can probably get away without clipping at all and simply wrap your box up like a present.
**Do NOT clip all the way to the board!  You will need the curves clipped to be able to glue it down properly on the other side but if you clip all the way to the board without accounting for the 1/8-1/4" depth of the actual foam core, you will end up with strays and strings that don't cover the depth of the board.

8.  Hot glue it all in place. Flip your board over and one little clipped part at a time, hot glue it all to the back.  If you didn't clip your curves, it will be immediately apparent that this is too difficult.  Take care around the corners and at the top.
**If you want, now's also the time to trim them with gimp or other cord-like decorative trim.  Just apply with a bead of hot glue!  I liked mine plain because the fabric seemed such a statement and in my "contemporary Gryffindor" style, I liked the ornate fabric and scallops against the clean surface.  And, I didn't trim out my pillows with fringe or gimp so I feel the whole style comes together better that way. 

9.  Paint or cover the inside of your box (optional).If you don't have a lot of depth from the wall, chances are no one will be able to see inside the box.  The only part of the insides I can see on mine is right at the low point of my scalloped corners; the rest is too slim and high for any of the inside hot glue work to be noticeable.  However, because I can see a bit of the inside sides of my cornice boxes, I opted to paint most of the inside black (which I had on hand in my design kit).  This reads like a shadow or simply fades from view and no one bothers to dwell on it.  You may want to think about painting the inside of your boxes black for the same reason.

10.  Hang 'em up!  Now, your uber-simple, cheap, lightweight boxes are finished.  Install one of your "L" brackets over one window.  Hold the second "L" bracket near the opposite end of the window and balance a board on it using a level to gauge accuracy.  You can measure both brackets from the ceiling height but I find this is less accurate than using a level (houses might be wonky) and typically takes more time to get right.  Then, while still holding your "L" bracket in place with one hand, discard the board and level and trade them for a screw and drill (or screwdriver).  Go ahead and screw that puppy into the wall.  Now, you have two "L" brackets above your window to hang your cornice box and that's exactly what you do.  Because these are so light, you don't need to anchor your "L" brackets or even affix your cornice boxes from below.  This means they simply lift off and on for easy dusting or even to change them with a different box!  So versatile, so easy.


Thanks!  Check out my other instructables for sewing and decorating ideas.  More to come soon!

Maker Moms Contest

Participated in the
Maker Moms Contest