DIY Window Seat Cushion + Video

By January 10, 2018Blog

If you would like to try your hand at creating your own custom window seat cushion, this post will give you all the info you need to transform your window area within a day. Before we get to step one, take a look at this video:

The video above shows me creating a window cushion for an area that is 116 inches long with a 16 inch seat width. Instead of making one long seat cushion, I made two 58”L x 16”W seat cushions. If your cushion size is different or if you choose to make one large cushion, you can still follow these steps. I will walk you through my process starting with the materials.

Fabric, quilt batting, polyurethane foam, board/wood base, staple gun, tape measure, and a sharp box cutter or kitchen knife will be your key materials. Helpful but optional materials include fabric scissors, T-Square ruler and sewing pins. (I would suggest comparing different store prices to see where you can find the best bargain for your budget.) For the wood base, some tutorials will suggest using plywood; however, I chose to use thin hardboard (⅛” thick). When deciding on your wood base, ask yourself, “do I plan to have people sit on this or use it for decor?” “Will I be frequently moving this cushion to different locations or will it remain in one area?” After asking myself these questions, I came to the conclusion this cushion would remain in one location for decorative purposes so a thin, lightweight base would be efficient. Keep in mind, the thinner your wood base, the shorter your staples should be in order to avoid being poked while sitting.

The “hardest” step in making your seat cushion will be measuring and gathering your materials. As long as you make sure that you are verifying all measurements upon each task, the process will be a breeze. Here are the 5 steps:

Step 1: Measure/Cut Foam and Hardboard
Once you have the length and width of the space you would like to place your cushion, the foam and board should be cut to that exact same length and width. For mine, the hardboard and foam were both cut to measure 58 inches in length and 16 inches in width. A sales associate at the home improvement store will be able to cut your wood to the size you need. However, I still needed to cut my foam because the fabric store would only cut the length but not the width. When cutting foam, it is important to use a sharp blade. Whether you use a box cutter or a sharp kitchen knife, be sure that you are not cutting the foam in a rough saw-like motion. “Score” the foam. Scoring is a cutting technique in which you use a repetitive cutting motion that will gradually make a clean cut rather than digging into the material in order to cut. Depending on the size of your foam, you may or may not have to worry about cutting your foam but I needed to cut a few inches off in order to make sure the foam would be the exact same length and width as my wood base/hardboard. When your foam and wood base are cut to the exact same size, begin step 2.

Step 2: Cut Batting
Quilt Batting is a material that is used between fabrics for insulation and most commonly used as the filler that makes quilts warm and heavy. The batting will be used in this project to help round out the harsh edges of the foam. This step is pretty simple and there is no way to mess this part up. Simply cut the batting large enough to blanket over your foam. In the video you may have noticed I used my wood base as a guideline to help me trace the shape of the cushion.

Step 3: Cut Fabric
Cutting your fabric is one of the most important steps. Measuring and making sure your work area is clean will remain key in this step because fabric is not cheap and the last thing you want to do is begin step 5 and realize your fabric is too short to staple or that you’ve stained your fabric in the process of your project. Making sure your fabric is inside out during this step will be helpful so if anything does come into contact with your fabric, it wont show on the face of the fabric.

As stated before, I needed to create a cushion for an area that is 116”L x 16”W but decided to make 2 identical pieces that are 58”L x 16”W. At the fabric store, they will cut the length of fabric you want but they will not cut the width. Just because you know the length and width of what your finished project will be does not mean you need to get fabric in that exact size. There will be some thinking and things to consider in order to make sure you have enough fabric to wrap around all sides without being too short. I’ve created a formula you can use to figure out the amount of fabric you will need. In this example I will be using my cushion’s length and width as an example, but of course you will need to plug in your own lengths and widths for these steps.

Thickness of foam and batting (or any other fillers you use) + Thickness of your wood base + 2 inches of fabric to be tucked and stapled. Multiply this total by 2 and then add the length of cushion.

Thickness of foam and any other fillers you may choose to add + Thickness of your wood base + 2 inches of fabric to be tucked and stapled. Multiply this total by 2 and then add the width of cushion.

So based on all of the information I’ve described that I would need, this is what my formula would look like:

2” + ¼” + 2” = 4 ¼” x 2 = 8.5” + 58” = 66.5 or 67” Length

2” + ¼” + 2” = 4 ¼” x 2 = 8.5” + 16” = 24.5 or 25” Width

Math may not be your thing so don’t freak out and think you need to enroll in college algebra in order to buy fabric. This formula shows that based on the thickness of my foam and board, I will need to add about 8 to 9 inches to my length and width. So to summarize, a 58”L x 16”W with 2” thick foam, ¼” thick board and 2” extra to staple, means I will need fabric that is 67”L x 25”W. (3 ft. = 1 yd. so I purchased 2 yards of fabric.) You can eyeball your project and make an estimated guess if that is easier for you. However, this formula may be helpful for making sure you do not buy too little or too much fabric. The last thing you want to do is pay for fabric just to realize you are short by only 2 inches and don’t have enough fabric to staple.

Step 4: Stack Materials in Order
You will now need to lay your fabric across a clean, flat surface. To make sure you do not staple your fabric facing the wrong way, be sure the face of the fabric is laying face-down. All you should see is the back of the fabric. Next, lay your batting down in the center of the fabric. On top of the batting, place your foam and make sure the batting is evenly spread around each side of your foam. Last, place your board on top of the foam. The foam and board should line up with each other evenly.

Step 5: Wrap and Staple
Now that your materials are all stacked, simply grab the outer edges of the fabric from your bottom layer and fold it up/over your board. Begin to staple each side starting from the middle and staple toward the corners to help keep your fabric tight and even on all sides. Leave about 1 inch between each staple. Staple all sides and save your corners for last. An upholstering course or detailed tutorial could inform you of the many different styles and techniques for corners. If you are just looking for a quick corner technique that will get the job done, I would suggest using the method you would use for wrapping a Christmas gift. Cutting off excess fabric may be necessary in this step. In my video, you will see that I had excess fabric but utilized alternative ways to staple and fold the fabric to prevent any parts of the cushion from looking clumpy. The best part about step 5 is that if you mess up, simply use a staple remover and re-staple.

Congratulations! You now have a window cushion that is ready to add style and comfort to your space.



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