I recently made a mermaid inspired costume with a sea shell bra for my Takane cosplay. I doubted any shell would be the right size while miraculously contouring my cups, so to avoid hover shells magically floating above my chest, I made a pair from scratch. Here's how...
*If you have a dressform you can probably skip to Step 2 and make the pattern directly on your dressform without using the KobraCast. Any reference to the "cast" will instead refer to your dressform. I do not own one, so I made a cast instead. *
Step 1: Cast you Cleavage
Put the bra you intend to use with your costume on either yourself. Cover the bra cups with plastic wrap to protect it from KobraCast residue.
Cut two pieces of KobraCast larger than an individual cup. You want to give yourself a little extra coverage beyond the cups because the shell may extend past the actual bra cup. Heat the KobraCast until it is at a molding temperature (Do not overheat!) then place above an individual cup. Mold to the contours of the bra cup by pushing at the centre then flattening and shaping as go move to the edges. You want to capture the details of the cups, the curve of the cleavage, and torso below the cups.
If you have trouble getting it right the first time, no worries. KobraCast is very forgiving. Reheat and try again. You can also sign up a lucky someone to help you out if you are casting directly on yourself.
Once cool, remove KobraCast. Ta-da, you have a cast of your cleavage! Then repeat for the other cup.
SAFETY TIP: KobraCast is safe to put on your skin since it is used for making medical casts (like the ones for broken arms). Once it is heated, test the temperature on safe spot on your skin to avoid burning yourself. If it’s too hot to hold in your hands then don’t put it on your boobs.
Step 2: Make a Pattern
Cover the cast in painter’s tape or masking tape by placing tape strips in one direction (vertical) then layer with strips in an alternate direction (horizontal). Overlap strips so that the pattern sticks together. Be sure to cover as much area as your shell should cover.
Trace the contours of the bra to serve as a guide for drawing the shell. Draw your seashell. Remove the tape from the cast, fortify with more tape where necessary, and cut out the seashell pattern. Since the pattern is three-dimensional (curved) you will have to cut darts to make it one-dimensional. Conveniently, these darts are similar to the look of a seashell. I cut out the orange outline as well as the dipped lines at the top of the shell pattern.
For my pattern, I decided not to cover the entire cup and left a little bit visible by the shoulder straps and the inner cup.
Repeat for the other cup. Label your items "Left" and "Right" to avoid mix ups.
Step 3: Trace the Pattern & Add Detailing
Trace the patterns on the foam then cut them out. I used a yoga mat from a dollarstore.
Add shape detailing: I added five little grooves at the bottom centre of the shell (cut into the foam with a blade in a V shape), as well as beveled edges (cut the edges with scissors on an angle).
Step 4: Heat Form & Shaping
Gently heat the foam and mold it to either the cast or straight to your cleavage. Once it cools and keeps the curve of the cups, glue together your darts with hot glue. You have a little leeway to adjust the curve of the shell by making longer darts before gluing them back together.
Step 5: Cover in Worbla
I used a single layer of Worbla instead of the “sandwich technique” for my shells (but both techniques could work). Cut a piece 2cm (1in) larger than their pattern size. Heat and shape to cover the foam shells. Make sure to keep the curve of the cup. Cut darts into the edge of the Worbla to make it easier to wrap around the shell’s edges and to prevent bubbles or puckering. Press Worbla into details such as bevels and embossed cuts.
Repeat for the other cup.
Step 6: Prep, Prime, Paint, & Seal
Step 7: Attach
Step 8: Become a Glorious Mermaid
I hope you found this helpful. If you use the tutorial, please share the results with me. I wanna see!
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