You will need:
1. A pattern - this can be self-drafted (recommended) or commercial.
>Self-drafted patterns are made to your measurements. They will still need some adjustment, but less than a commercial pattern. They take 1-2 hours to draft. Materials needed for self-drafting: rulers (centimeters work best for the math involved), large paper, pencils, calculator.
>Commercial patterns, such as those from big-brands like Simplicity and McCall, as well as patterns from independent patternmakers are ready-made with "sample" measurements that represent an average. There is not as much work on the front-end to design the pattern, but there may be more on the back-end to get it to fit your body. Example: I must always add length to the waist of commercial patterns.
2. Sturdy scrap fabric, 2-4 yards - this will be used to make the mock-up(s) of your pattern to allow you to see where adjustments need to be made.
3. Coutil or sturdy canvas, 2-4 yards - Coutil is the traditional interlining for corsets. A sturdy canvas with as little stretch as possible is an acceptable substitute. This will be used in the mock-ups as well as the final product.
4. Fashion fabric, 1-2 yards - this will be the outside of your finished product. Non-stretch and sturdy fabrics highly recommended. Cotton will keep it breathable, polyester or silk will make it a little warmer.
(Aside: I keep saying "sturdy" and I mean it as "something akin to quilting cotton, maybe a little thicker like some upholstery fabric.")
5. Lining fabric, 1-2 yards, optional - Corsets will always have 2 layers of fabric, but you have an option for a third layer to cover the coutil/canvas if you wish. This should counter your fashion fabric in weight - if you have chosen an upholstery fabric for your fashion layer, maybe pick a cotton for the liner. Overall we don't want it to be too thick.
6. Bones, variable amount - You will need some flat steel bones for the center front and center back of the corset, as well as either spring steel, synthetic whalebone, or zip ties. These three options are flexible enough to deal with curves over busts and at sides, and durable enough not to buckle and dig in to the body.
>Spring steel is the only one of these that I have worked with and I have had great success with it. It does make washing the item difficult for fear of rust, and tipping them can be tricky.
>I have spoken with very few people that have used synthetic whalebone as it is expensive. There are many people online that will use a Dremel tool to file down the edges and forego the use of tips.
>Heavy-duty zip ties are very popular for corsetmakers both starting out and professional. I have never used them as I am afraid they will buckle, and there is nothing as bad as a buckled bone in a corset for garment discomfort. Have I seen evidence of this happening? No. I am just irrational.
7. Bone tips, variable amount to equal 2 times the number of bones - Bone tips prevent the bones from cutting through your fabric and poking out to make you a bloody mess (yes, personal experience, still not sure how my corset wasn't stained). There are several options here:
>Metal tips - these are little caps that get bent to the ends of the bones. They have a tendency to slide off, however, so I usually pair these with the Plasti Dip method. I find that they also take 2 pairs of pliers and a lot of hand pain for those of us with repetitive stress injuries.
>Plasti Dip - I'm not sure I would trust this on its own with flat steel bones, but it is great for sealing metal tips on and the rubberization is great for keeping the bones from slipping around inside their casings/channels. It does take a long time to fully cure, which adds time to the length of the project.
>Heat-shrink tubing - fast and easy and painless. If I could reliably find heat-shrink tubing in the appropriate sizes this would be my go-to for 99% of boned projects.
8. Bone casings, conditionally optional - These will be sewn inside the corset and will house the bones. It can be ribbon, bias tape, or purpose-made corset bone casing. I have only used bias tape and have never had a problem. The casing should be slightly wider than the bones to keep them stationary. If you will be lining the corset, you have the option to skip casings and sew channels directly into the corset for the bones to occupy.
9. A busk, length variable, optional - Busks come in a variety of form factors depending on the era of corset you are making, from a single piece of wood, bone, or metal, to a split-front affair that will allow you to fully open your corset from the front. You can skip this piece by having a row of lacing in the front, or by having a solid-front corset that you wiggle over your head (in this case you would just add more flat steel bones to keep the structure). The length is equal to the center front length of the corset and will be taken from the final pattern after alterations.
10. Grommets, size 00, variable amount - These are the little metal bits that the lacing passes through to cinch the corset in. You will need a lot. I specify size 00 because I have that size die for my grommet press and it takes about 2 hours off the whole process to use that. This size is also about 3/8" in diameter, which means you can put more of them in to help distribute the pull of the laces more evenly.
11. Binding, optional but recommended - This is will cover the top and bottom edges of the corset and help to hold your bones in place. It can be the same as your fashion fabric or something to complement or contrast it. Alternatively, the corset can be sewn without binding but I find that it looks less polished that way.
12. Lacing, variable amount - It is longer than you think. Longer. Little more. There you go. The more reduction you want in your corset the fewer options you have for this. I have used thin paracord (works great, easy to find, a little bulky, obviously non-period), macramé cord (hate it, need to replace, way too bulky), and purpose-made corset lacing (of course this is my favorite, not expensive, limited colors but highly dyeable).
I buy most of my supplies at https://corsetmaking.com/.
Estimated Time 5-10 hours:
Pattern drafting ~1 hour
Mock-up and adjustments ~1-3 hours depending on how many adjustments are needed
Cutting & tipping bones ~1-2 hours depending on tipping method, much longer if using Plasti Dip
Sewing corset, setting bones and grommets, and binding ~2-4 hours
About the Process:
Once you get your pattern right you can use it over and over to make that style of corset as many times as you like. You can make notes on it regarding boning lengths, etc, to speed up the process as well. As long as you pay attention to your fabric grain and use a good interlining (the coutil or canvas) you shouldn't have any trouble with the finished product and the process gets a lot faster.
