Process

Prototypes

To see how my design will turn out, I tried making a rough prototype. Initially, I planned to make my bag using leather, interfacing it with a form (cut into diagonal pieces so that when joined, it forms a circumferential shape, like the Igisabo shape), and then lining it with pure cotton fabric. For the materials, I also planned to use natural animal leather. To make my leather unique, I decided to dye it using the tie-dye technique to create a bullseye pattern inspired by the concentric circles found in Imigongo art. Here is what I have managed to make so far.

PROTOTYPING WITH MATERIALS

I planned to buy cow leather directly from slaughterhouses and treat it to the final stage, ready to be used. However, due to the limited time left to work on and finish our projects, I realized that preparing this animal pelt would take too long. Therefore, I decided to work with local vendors who supply prepared animal leather that is still pure (hairless and not yet dyed). I bought it from them and dyed it myself using red onion dye.

Here are the steps I followed to dye a small swatch of leather to see how it would turn out.

Materials Used:

Red onion skins (from about 6 onions). Water (1 liter). Cow leather. Mordant: Vinegar (80 mL).

Step 1: Prepare the Dye I collected onion skins from about 6 onions. The skins were mostly dry and had a rich red-purple color. I boiled the onion skins in 1 liter of water for about 1 hour. As the skins boiled, the water turned a deep brown color, which is the natural dye. After boiling, I strained the liquid to remove the onion skins, leaving only the dye solution.

Step 2: Mix with Vinegar I added vinegar to the dye solution and mixed it for around 3–5 minutes.

Step 3: Tying the Leather I tied the leather in a pattern, but I realized that because leather is a bit thicker, tying it tightly to create a bullseye pattern might prevent the dye from reaching some parts of the leather texture. So, I decided to do what was possible which is Peak Tie Technique by tying some parts of the leather randomly. Since this swatch was small, I tied it only once. I did this because the most important goal was to achieve a unique leather look.

Here is how I was supposed to tie my leather to achieve bullseye patterns.

However, I ended up using the Peak Tie Technique because of the thickness of the leather (it is not easy to fold the way you want).

how Peak Tie technique done

The results are fragmented circles after dyeing, depending on how you tie the material. Since my swatch was small, I only tied it once.

Step 4: Soaking the Leather I soaked the leather in the dye solution, gently mixed it, and left it in the dye bath overnight to achieve a deeper color.

Step 5: Rinse and Dry After dyeing, I rinsed the tied leather in cold water to remove any excess dye and stop the chemical reactions. Then, I untied the leather and hung it to air dry.

The above are the steps I followed to dye my leather, and here are the results with fragmented circle.

PROTOTYPING WITH DESIG

For the design, I first start by creating a sample molds for duty prototype in SolidWorks software using tools like the Mold Tools Toolbar, Draft Analysis, Parting Line Analysis, Parting Surfaces, Shut-off Surfaces, Tooling Split, and Undercut Analysis tools. After designing the mold in SolidWorks, I save the design as an STL file by selecting File > Save As and choosing the STL format, adjusting the resolution settings for optimal quality. Next, I open the STL file in slicing software (e.g., Cura or PrusaSlicer) to evaluate and repair any errors, such as gaps or inverted normals, and ensure proper orientation for printing. Using the slicing software, I convert the STL file into G-code, setting parameters like layer height, infill, and supports, and preview how the printer will build the mold layer by layer. Finally, I transfer the G-code to the 3D printer, print the mold, and clean off any support material after completion. This process ensures the mold is accurately translated from the digital design to a physical 3D-printed object.

I have also tested the molding process to see if it would work by creating a 3D mold. I used paper to see how it would turn out, but it ended up looking fully wrinkled. I realized that creating a 3D mold with no joints sometimes does not work perfectly. I then thought of molding one half of the design first and molding the other half separately. After successfully achieving the desired shape, I plan to join the two parts using wax thread.

I have also made rough prototypes for the interfacing (using EVA foam) and the lining. I created this prototype using heavy, strong interfacing by cutting the patterns diagonally so that when the parts are joined, they form the shape of our Igisabo design.

MIDTERM PRESENTATION

The Essence of Threads of Heritage

Threads of Heritage is a modern, sustainable bag inspired by the traditional Rwandan igisabo. Made from upcycled leather and natural dyes, it celebrates Rwandan cultural heritage, promotes eco-friendly fashion, and empowers women by honoring their strength and resilience. This bag is for anyone who values unique, meaningful design and wants to support cultural preservation, sustainability, and women’s empowerment.

Mentoring notes

from Claudia

Might not need to use EVA foam tho. I would go back to the shape, try to explore a bit more variations, get 3d scan with Kiri engine from your phone and use meshmixer to redesign it more contemporary, also exploring personalisation. All igisabos are slightly different at the end.

from Anastasia

-I think you can also explore the modular fashion! i recently saw very nice leather bags with no stitches !

-Also, in terms of the internal lining, i have leather bags that do not have lining. but if you want to put some lining, i was thinking that it could be interesting to use this kind of very typical.

from Troy

If molding the full 3D design of your project is not working, I think you can separate your design into two parts, mold those parts separately, and then join them afterward. To determine the amount of material needed, you can use a zero tape by attaching it fully to your molds, carefully removing it, and then spreading it on the main material you will use for molding.

Half-fabrication files

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1. Test file: 3d modelling test ↩