How to Make an Infinity Dress
There are many tutorials on how to make an infinity dress. While I found them to be helpful, I was shocked to find how many glossed over essential steps and did not include the basic math needed to make this dress. Also - none of them included pockets!
As I need to attend a wedding and had nothing appropriate in my closet that fits right now, the infinity dress seemed like a good, maternity-friendly choice that will (hopefully) continue to fit postpartum.
In this tutorial, we'll walk through all of the math needed and detailed step-by-step instructions on how to make an infinity dress with lined straps for a little support and, importantly, pockets.
Q: What do I need to make an infinity dress?
A: To make this dress, you will need:
Fabric (see notes below on selection and how much is needed)
1/2 yd - 1 yd Power mesh (optional - see notes below)
Fabric scissors and/or rotary cutter with cutting mat
Rulers and/or yardstick
Pattern weights (optional but recommended)
Straight pins and/or hem clips
Sewing machine with zig-zag stitch or similar
A ballpoint needle for the sewing machine
Pocket pattern (see tutorial here for how to make your own)
Flexible measuring tape
Q: How long does this project take?
A: Not as long as you'd think. I spent about 2 hours cutting out the pieces and about 3 hours sewing everything together. You could absolutely make this dress in a day of dedicated sewing.
Q: How difficult is this project?
A: The most difficult part of this project is dealing with the stretchy fabric. The fabric I chose (notes below) is quite slippery which gives it a beautiful drape and makes it feisty to work with. Beyond that, this dress is essentially a circle skirt with rectangles stitched to the top. I would call this a medium or advanced beginner level project.
Taking Measurements and Doing some Math
Before you can order your fabric, you'll need to figure out how much you need. This is largely determined by the length of the skirt.
(Measuring) First, take the following measurements:
Waist = w inches
Skirt length = L inches
Height = h inches
Breast/chest width = b inches (this should be the amount of fabric needed to cover a single breast or pectoral, with some overlap at the center)
Breast/chest height = t inches (the amount of fabric needed to line the strap from bottom of a single breast or pectoral to wherever makes you feel comfortable)
s = seam allowance (I will be using 1/2 inch)
Measuring on your own? Clip hem clips or binder clips to your sewing measuring tape around where you think you want the skirt length. Then, hang the tape from your waist and use a mirror to decide which marker is the correct length. Adjust and repeat as needed.
Now we can do some math!
(Skirt math) Let w = waist measurement = skirt opening circumference
What we need to find is the radius of the opening so we can draw it out on fabric. Because the fabric we'll use is stretchy AND cutting a circle skirt causes most of the lines to be on the bias, we'll subtract one inch from the measure before finding the radius (included in the equation below). We'll also let π = 3.14 for the sake of rounding.
To find the radius, use the following equation:
r = (w -1) / 6.28
Remember your order of operations! Do the subtraction before the division. For my waist measurement of 33 inches, this gives a radius r = 5.09 inches. Round down to the nearest quarter inch - for me that's 5 inches.
Next, we must account for seam allowance. Take r - s to get the final radius of the skirt opening. For my measurements, that's 4.5 inches. This is the radius I will use when actually drawing out my pattern.
The last piece of the skirt is the length as measured from the opening. This is simply L. For me, L = 35 inches. As long as your fabric will not fray, there's no need to account for seam allowance as you won't need to hem it. If you want to hem it anyway, use L + s instead.
(Strap math) The other measure we need is how large to cut the straps. This is pretty straightforward and the easiest way to get the right ballpark measure is to use height, h.
To get our strap length, use 1.5 x h. For me, that's 1.5 x 67 inches = 100.5 inches. Round down to the nearest inch (100 inches).
This was ultimately a bit long and I trimmed the straps by 10 inches after finishing the rest of the dress. Again, we will not need to hem the straps as long as we use fabric that will not fray.
To get the width of each strap, simply use b inches (width to cover one breast/pectoral). We will need some seam allowance in this direction because we're going to line the first part of the strap. So the final width will be b + 2s. For me, this measurement was 14 + 1 = 15 inches.
The final measurements for your straps are then (1.5h) by (b + 2s), remember you will need two straps!
To line the straps, the lining will be the same width as the strap (b + 2s) with a height of (t + s) as only one end of the lining will be stitched. If you plan to use power mesh as a middle layer of the lining, this is the dimension needed for that as well. For me, this gives 15 inches by 10.5 inches for the lining.
(Making a cutting diagram) To make your cutting diagram and determine how much fabric to purchase, reference the image below, substituting your own measurements into the diagram.
First, make sure that your fabric width is wide enough to use the diagram. That is, that the skirt width and lining will fit within the fabric's width together. Use the total length of the skirt with it's waist radius and the width of the strap to check this: r + L + b + 2s. For me, that's 5 + 35 + 14 + 2(0.5) = 55 inches. No problem for 60 inch wide fabric.
Next, calculate the amount of fabric you'll need to order using the length of the straps, 1.5h. With my measurements, I rounded to 100 inches. Now remember that you need TWO straps and the cutting diagram shown needs to be repeated at the other end of the fabric. To do this, double the number. For me, that's 200 inches = 5.5 yards. I always recommend rounding up to purchase an extra 1/2 yard just in case of mistakes, so I purchased 6 yards of 60 inch wide fabric.
Notes on Materials
(Fabric) When choosing fabric for this project, start by filtering out anything that doesn't meet your width requirement as calculated above. If you didn't bother with the math, stick to around 60 inches wide.
What you want to look for beyond the width is a good amount of stretch, I recommend 40 - 50% 4-way stretch for comfort. If you're shopping in-store, grab a section of the fabric and stretch it. It should stretch about half the length of the amount you grabbed. That is, if you hold a 4 inch section, it should stretch an additional 2 inches to reach 6 inches total - that's a 50% stretch. Check this in both directions along the fabric. If it stretches like this both ways, that's a 50% 4-way stretch.
I also recommend looking for a good drape. The fabric should fall elegantly over your body and around your shoulders. This is particularly important for the straps which will need to be able to twist and bunch up easily.
Generally speaking, if the fabric meets the requirements above, it's going to travel well and shouldn't wrinkle easily. This is key for the straps which will be scrunched up and manipulated heavily, allowing you to change the style of the dress at any time. No wrinkles here!
Finally, check the cut edges to make sure it won't fray. Again, if it's meeting the requirements above, this should not be an issue. In a perfect world, the edge won't curl either but that's much harder to find.
I used Telio Brazil Stretch ITY Jersey in Wine from Fabric.com.
(Power mesh) I wanted a little bit of support in the straps and decided to line the first bit with some power mesh to provide it. Power mesh is a mesh fabric that stretches well in one direction but not at all in the other. This means one direction can be used to provide support while the other direction continues to be stretchy and comfortable. It's a great choice for lining athletic wear and knit lingerie. This characteristic also makes it a great fit for breast/chest support in dresses when you won't want to wear a bra. Note, however, that it will do nothing for nipple control.
In total, you will only need enough to cut out the lining, so ordering 1/2 - 1 yard should be enough. I bought mine here on Fabric.com. The color is currently out of stock but it's available in many colors by searching "power mesh."
Making an Infinity Dress
Now that you have your cutting diagram and all your supplies, let's make the dress! Follow the steps below.
(Step 1 - cut out the skirt) Fold the fabric to the needed length (half of your strap length) and smooth it out. This is more difficult than you would think as the fabric can be quite slippery. Use pattern weights to help make it behave.
In the corner near the fold, place a pin or clip to mark your skirt center. Measure and mark around it from the fold to the selvedge edge using the skirt opening radius you calculated earlier, r - s (4.5 inches for my measurements). Connect the dots to make a smooth quarter circle.
Again measuring from the skirt center mark, measure out the length of your skirt PLUS the unadjusted radius: r + L. For my 35 inch length, that gives 5 + 35 = 40 inches. It may seem easier to measure from the line you already drew, but this will be more consistent. Again draw a full quarter circle with this measurement starting at the folded edge and working towards the selvedge. Add a line along the selvedge edge, perpendicular to the folded edge, to complete the quarter circle.
Carefully cut out the skirt. You should have a full half circle piece due to cutting on the fold.
(Step 2 - cut out the strap) With the fabric still folded in half, measure out a rectangle using half the strap length away from the fold by the strap width. With my measurements, this was 50 inches x 15 inches. Carefully cut with a rotary cutter or fabric scissors.
(Step 3 - do it again) Repeat steps 1 and 2 on the opposite end of the fabric. You should now have two half circle skirt pieces and two straps.
(Step 4 - the remaining pieces) Cut out the lining and pocket pieces using the remaining fabric. Reference your measurements from above. My lining was 15 inches x 10.5 inches.
Remember to also cut the lining out of the power mesh, if you will use it, paying close attention to the direction the fabric stretches. The stretch should go across the chest with the non-stretch direction going up and down the body.
Now that we're ready go sew - go prep and check your machine. Make sure there is a ballpoint needle in the machine, the stitch is set to zig-zag or stretch stitch, and the tension is behaving itself.
(Step 5) Place the power mesh lining on the wrong side of the dress fabric lining. Pin and baste around the edges, staying within the seam allowance. If you're not using power mesh, skip this step.
(Step 6) With right sides together, pin the lining pieces to one end of the straps. Do not pin along the top. Stitch around the sides and bottom of the pinned seam. Clip and trim the edges, then turn the fabric so the right sides of both lining and strap are facing out. Press.
(Step 7) With the right side of one skirt piece facing up, lay the pocket pieces with right sides down on either side of the skirt opening. The short ends of your pocket pieces should match up with the flat part of the skirt and the top of the pocket should meet the skirt opening. Pin in place. Repeat for the other skirt piece. Stitch these short seams. Flip the pocket over the skirt piece and press in place. If the pockets seem confusing, reference the more detailed pocket tutorial here.
(Step 8) Match up both skirt halves with right sides facing. The pockets should be out at the sides. Pin from the top of the pocket, around the pocket, then all the way down the side of the skirt seam. Repeat on the other pocket and seam. Stitch along the seam, then trim if needed. Turn the skirt right sides out.
(Step 9) Overlap the straps to whatever degree makes you comfortable. Pin in place. My straps are overlapped by about 2 inches. Alternatively, choose not to overlap them at all and skip this step.
(Step 10) Find and mark the center of the skirt front (the front and back are the same - just pick your favorite side). Match up the center of your straps with right sides facing the skirt. Double check the right side of the straps are facing the skirt so the lining will appear on the inside.
Pin the skirt to the straps in both directions. Depending on how wide you made the straps, they may go past the side seams and that's OK. Grab the pockets and add them to the seam so they are going towards the front center.
Stitch across the seam slowly as there are quite a few layers here. Trim if needed.
(Step 11) Along the back of the skirt center, fold down the seam allowance towards the wrong side of the skirt and clip or pin in place. This should adjust the top edge so it's even with the front seam line. Stitch in place.
(Step 12) Try on the dress and explore the possibilities with the straps! You're all done!
That's it for this post, friends! I hope you enjoyed it and were able to make your own infinity dress! If you make this dress, be sure to tag me @craftematics on your favorite social media.
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