Amethyst Costume Build

3D Printing! Resin Pouring! CircuitPython! Body Makeup! Beard Dye! In this Halloween build, what started out as simple became a fun journey in learning so many new skills. The result: a live action version of Amethyst, one of my favorite characters from the show Steven Universe.

In this tutorial I'll cover the broad strokes of every part of the build, with deep dives into the whip & gem builds. I hope to impress the spirit of trying things out for a little joyous exploration.

For many of these items, I link to what I used, but feel empowered to use your own variations!

Whip

• Translucent purple PLA filament*
• White PLA filament*
• Super Glue*
• Dark Gray Paint Marker
• Black Paint Marker
• Light Pink Paint Marker
• Resin Coating*
• 3 upcycled cables (I used shorted/broken computer power cables)

Gem

• Translucent purple PLA filament*
• White PLA filament*
• Super Glue*
• Resin Coating*
• Hot Glue
• Gemma M0
• Strip of 8 LED lights
• Lithium Ion Battery
• Magnets
• On/Off Switch
• Liquid Latex
• 2 bolts

Body Paint

• Toner
• Purple Makeup
• White Makeup
• Setting Powder
• Finishing Spray

Outfit

• Light purple tank
• Black tank undershirt
• Black jeans
• Wig

Used in build but not final parts:

• Painters Tape
• Wax Paper
• Small Boxes (for stabilizing during pours)
• Clippers
• Sandpaper
• Heat gun
• Makeup brush
• Sponge
• Deli containers (for resin mixing)
• Exacto knife

*Used in multiple parts

I picked this costume to learn 3D printing- much of the parts were made from this. I used a combination of models and modified a few.

I've included some of the failed prints to show how much of a slog it was at first to figure out how to print. My first 10 prints were complete failures- by the end every print was successful unless I was trying to decrease weight and chose a design that wasn't possible. Keep trying! You'll get there.

Gem

For the gem, I used this wonderful model from MechEngineerMike on cults 3D. It was the only paid model for this build- but it was well worth it. I tried a few variations of fills, and landed on (the recommendation of Mike) of using a completely solid fill for the gem face and diffuser, and 20% fill for everything else. This allowed the light to go through solid print and not show an infill pattern.

I scaled the gem up to 170% after seeing the original model on my chest. I also modified the diffuser a bit to have an extra arm and cap to evenly diffuse the light. I hope to get better at model design, this was my first time using Blender and I could not get the parts to perfectly connect. BUT! It did it's job, so I hot glued it together and called it a day.

Whip

Oh boi this whip occupied a lot of research space and trial and error. I landed on using most of the parts from this model scaled to different sizes, then I modified the handle on this other model since I wanted a solid handle. Attached is the modified STL. I took the spikes from the first model and scaled them to a few sizes, between 110% to 60%.

I painted the hilt light pink and the handle a combination of black and dark neutral gray using paint markers.

For both the gem and whip, I used clippers and sand paper of grit 60 - 320 to clean up each print.

After trial and error on a few PLA smoothing methods, I landed on resin pouring. This was tons of fun! I taped down boxes and wax paper to protect my desk, put on a respirator, and mixed the 2-1 resin mixture. I did it in a few batches because the mixture started to harden quickly, and I wanted to ensure the pour was evenly coated.

I poured resin on the gem, whip base, hilt, thorns, tips (not the handle). I also aligned, taped, and poured resin on magnets on the back of the gem and the connecting piece. The idea was that the magnet could go behind any clothing to hold the gem to it, but that did not hold up enough weight. More on that later!

After 16ish hours, I removed the hardened parts and used an exacto knife to clean up the edges.

To ensure the whip stayed together, I kept the plug end of the cords on, and shoved them into the body of the base. I then glued the two sides together.

I threaded the handle and hilt onto the end, and super glued each part together. To ensure the most solid handle and add weight, I poured resin down the hilt, encasing the cord ends into the body of the handle.

This is when a *happy little accident* occurred- the resin got so hot inside the handle that it bent the handle a bit! To me, this actually turned out better, since the whip is already a little curved it would make sense to have a curve in the handle.

I then braided the cords using a three strand braid. I glued a few points along the whip to keep it together, and left about 20" of the three cords unbraided.

Since the whip tips did not come in two parts, I needed to cut the cord ends and opted to super glue them in. For extra umph, I also poured resin into the tips. This took some creative stand creation- I draped the whip over a high up point to take the weight off and used a box and tape to create small cradles for each tip. 16 hours later, and voila! Solid body whip tips.

Lastly, I added the thorns, distributing them along the whip in decreasing size, adhering them with super glue.

The gem setup and code was rather simple. I wanted white lights to pulse, with the opportunity to change if I wanted to create patterns and inputs. To be honest- this probably would have been even simpler if I just purchased a small strand of fairy lights. But hey, I had many of these parts.

I wired the power, ground, and data to a strip of 8 LEDs. I used CircuitPython to run code, which means I did not need to mess with the Arduino IDE and could run python code directly on the Gemma.

Here's my code:

import time
import board
from rainbowio import colorwheel
import neopixel


pixel_pin = board.A1
num_pixels = 8


pixels = neopixel.NeoPixel(pixel_pin, num_pixels, brightness=1, auto_write=False)


WHITE = (255, 255, 255)


brightness = 0
startup = True 


while True:


    time.sleep(0.01)


    if startup:
        brightness += 0.01


        if brightness < 1.0:
            pixels.fill((brightness * 255, brightness * 255, brightness * 255))


        else:
            startup = False
        
    if not startup:
        brightness -= 0.01


        if brightness > 0.5:
            pixels.fill((brightness * 255, brightness * 255, brightness * 255))
        else: 
            startup = True


    pixels.show()

In laymen terms, the lights get brighter until it meats full brightness, then oscillate between brightening and darkening halfway.

NOTE: When using CircuitPython, don't forget to use a data usb cable! This issue had me debugging for a while.

I also added a switch between the battery power and board, knowing from past builds that this greatly increases accessibility and protects the battery JST ports.

The shirt I had did not have quite enough of a neck hole to have a drop sleeve like Amethyst, so I widened the neck just passed the binding, and that did it! A strap that would surely disappoint Pearl.

For the jeans, I drew boundaries with the pants on, then drew stars between the box with them off. While they look like stars with them off, these did not turn out exactly as expected. I will probably add a thin layer to keep the star shape on future wears or projects!

I also picked power boots to match the personality of Amethyst- white high top dockers.

All clothing except for the shoes were thrifted.

This was a BLAST. I have always wanted to dye my beard and hair, and this was a perfect excuse for it. In total, this took ~5hours with a professional.

NOTE: When using around your nose and mouth, be sure to allow for fresh air!

To maintain the hair after dying, I used jojoba oil and no yellow shampoo. The purple faded a few weeks in, but it's left a nice silvery look.

Even though I dyed my hair, it wasn't quite long enough to appease Amethyst's mane, so I wore a wig when in full costume.

To get Amethysts skin, I covered my arms, shoulders, top of my chest, face, neck, ears, and exposed knees.

I started with the skin toner, allowing that to dry.

Then I applied color- one layer of white, then two-three layers of purple. I used a wet sponge and a lot of patience.

After that I brushed some setting powder, then a layer of setting spray.

Overall this took 2-3 hours, with limited access to anything else during the process. I learned after the first application to not do the palms of my hand, as they would quickly rub off anyway. I am still cleaning purple off of surfaces.

For my face makeup, I went with a dark grey lip and some sparkly purple pigment around my eyes.

Assembling the gem was so cool! I stopped by my local hardware store to find bolts that fit the scaled up model. I tucked the cables behind the diffuser, and taped the switch to be exposed in the back of the gem.

The magnets neatly aligned and clipped to the body. After attaching the gem to my black undershirt using the magnets and doing a dance test, it was readily apparent that they would not keep. So! I tried a lot of different techniques. I landed on applying liquid latex to my chest, then super gluing the back of the gem to the liquid latex. This worked and looked really great for most of the night.

Note: If I were to do this again, I would just use some fishing line or a chain around my neck. While the latex protected me from direct adhesion, gluing it to my chest was a lot of effort and a lot of lost hair. Do not recommend.

Amethyst is all about being carefree and kind. She transforms often, and loves new experiences. Embody that in your Amethyst costume. But please be safe when testing your whip.

Thanks for reading, and please don't hesitate to ask any questions, give feedback, and let me know what ya like about this build!