When I stumbled upon the world’s cutest mer-kitty fabric, I had to find a project for it. I considered a spot in the tiki room. But ultimately this fabric was destined to be a window valance in my pink bathroom.
Just look at it! The mer-cat’s martini is garnished with a fish, and the retro mermaids are #stylegoals.
Window valance curtains are very simple to DIY, and they have a charming mid-century look. Here’s how to make your own.
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Window Valance Tutorial
1. Gather Materials
- Fabric (I used half a yard of this fabric in lightweight cotton twill)
- Measuring tape
- Scissors (or rotary cutter and mat)
- Iron and ironing board
- Sewing pins
- Sewing machine and thread
- Tension rod or your preferred curtain rod
Where to Get Mer-Kitty Fabric
Spoonflower is the place to go for adorable mid-century style fabric and other products designed by artists. You can select the type of material you want a design printed on, and some fabrics come in different sizes (see the fabric options).
I ordered one yard of Martini Mermaids on Coral in lightweight cotton twill, which is 58 x 36 inches.

The designer, Miss Fluff, has a whole line of retro pinup style designs, including mermaid fabric with an aqua background if you prefer that over pink.
2. Cut Fabric
Start by measuring your window. Cut the fabric to the desired size, leaving a 1-inch hem allowance for each side, 3.5 inches for the rod pocket on top, and at least a 1-inch hem allowance on the bottom.
You can make your valance as wide or long as you like for your window. Here are some sizing formulas to help.
Sizing Your Valance Width
Generally, a valance is a short curtain mounted above the window to hide curtain hardware. The common advice is to make curtains at least twice the width of the window for fullness.
For a standard valance curtain, use this formula: (2 x window width) + hem allowance = fabric width
I wanted a flush-mount valance hanging on a tension rod inside the window, and I didn’t want it to be too bulky. In that case, I recommend sizing the curtain to 1.5 times the window width.
For a flush-mount valance curtain like mine, use this formula: (1.5 x window width) + hem allowance = fabric width
Here’s how this formula works for my 34-inch window: (1.5 x 34 inches) + 2 inches = 53 inches

Related: See this mid-century bathroom makeover
Valance sizing is really a matter of preference. You may want to bunch up some fabric on a curtain rod to compare different widths.
If your fabric isn’t wide enough, you can hang two valance curtains side by side. Some people also opt for modern flat panel valances like this.
Sizing Your Valance Length
For the length, it depends on the window. If you have enough fabric, I suggest leaving the bottom a little long for now and testing out the length in step 5.
Generally around 25-40% of the window height will look good.
But for a tall window, 40% might look so long that your curtain no longer has that short valance look. In that case, you might want to stay under 16 inches or so.

Related: How to find mid-century modern curtains
Since my window is so short, and I wanted to use quite a bit of the pretty fabric, I made my curtains close to 40% of the window height at 13 inches tall.
Again, make sure to leave 3.5 inches of hem allowance for the top and 1 inch of hem allowance for the bottom. Ultimately, my fabric cutting was 53 inches wide by 16.5 inches tall.
3. Hem Sides of Fabric
Now fold the left side over half an inch and iron it. Then fold it another half an inch to hide the raw edges. Iron and pin it in place. Sew straight up the left side.
Repeat this for the right side, so both sides are hemmed.
You might want to test the fabric on the rod again to make sure you’re happy with the width or see if you want to size it down.

4. Sew the Rod Pocket
Next, fold the top of the fabric over half an inch and iron it. Then fold that over 3 inches (or big enough for your curtain rod) and iron and pin the fabric.

Sew straight across the bottom of your rod pocket, making sure there’s room for your curtain rod.
5. Hem Bottom of Curtain
Finally, test the length of your valance. Hang the curtain in your window and pin the bottom of the fabric up until you figure out which length looks best.
Take down the curtain and cut the bottom of the fabric to your desired length plus a 1-inch hem allowance. Fold the bottom over half an inch and iron. Then fold it another half an inch, iron and pin it in place.

Sew straight across that bottom hem, and your curtain is ready!
6. Hang Your Window Valance
I like the look and ease of a flush-mount tension rod for hanging valances, or you could go for a standard curtain rod above the window.
Here are some ideas.
You might also like these curtain decor guides.
Mermaids and Mer-kitties..perfect for your pink bathroom! (I like the little crab at the bottom. 🙂 ) I love that Charlie is checking it out too! I wondered what you had gotten this piece of fabric for when you showed the extra piece the other day. It turned out awesome for a valance and looks great! Go you!! (Also great instructions on how to make a valance.)
Haha, both cats had to check out the new curtain right away! They approve. 🙂 There are so many cute details on this fabric…yes, the little crab! And the flowers and fish. And especially the mer-kitties! Just what this pink bathroom needed. 🙂
So cute! I think the cat’s beverage is a Tuna Colada.
Haha, I think you’re right! Charlie and Jane are going to want a Tuna Colada now. 😀