Introduction: Encased - Body Shaped Leather Lugguge
The body is a sculpture: It's constantly in motion, yet every frame of the movement is a unique sculpture in itself. To create a sculpture of the body is not just about capturing a body posture; it's more about capturing the energy and recreating the emotions/sensations at that specific moment. Observing sculptures by Rodin and Bernini, you'll notice that a seemingly static representation of the body can still be full of tension, and you can almost feel it through your own skin.
Encased is a collection of body shaped leather luggage that seeks to freeze a moment of the body while still maintaining the energy and sensations at that moment.
Step 1: Visual Research
I started out by collecting images of body sculptures and body photography. I had two criteria in choosing these images:
1. Architectural beauty in the anatomy of the body
2. Tension, emotions & sensations: how the body posture is framed in a way to achieve a perfect balance between the imagery of the body and the energy of the moment ; how to NOT describe the body in a literal way but still maintain the sensuality of the body.
Step 2: Body Scan
Based on the previous visual research on the body, I roughly sketched out the body postures I wish to capture. The actual body scan process is pretty straightforward with the free app 123D Catch by Autodesk. With 123D Catch you basically take 20-30 photos around an object, upload the photos, and then you get a 3d model of the object. The key here is to find a evenly lit environment for the photoshoot to maximize the resolution of the captured model.
Once the scan is all done, the next step is to clean up the scan - deleting the background geometries and any other unwanted parts. Here I used MeshMixer, another free software by Autodesk. By using the "plane cut" function you can easily clear the extra geometries around your object.
Step 3: Prepare Model for CNC Machining
After I had the scans of the body cleaned, the next step (a very important one) is to decide how to "frame" the models. The process is similar to cropping/editing in photography. I screen-captured different perspectives for each scan, printed them out and sketched on top of them to find out the best representation of that body posture.
After a rigorous analysis of all the screen captures, I chose three of them as the final shapes for molding leather. In Meshmixer, I smoothed out the scanned models more, and used the sculpting tools to highlight some of the anatomical features. I also reduced all the sharp angles and dramatic geometry changes, because the stretchiness of leather is only to a certain degree and it can't form into a shape that has very dramatic geometries. The body model was then joined with a block shape to create the model of a male plug for leather molding.
Lastly I exported the models from Meshmixer to Rhino, where I adjusted the dimensions and used boolean difference to create the female plugs (negative shape of the male plug).
Step 4: Stock Prep
The stocks for machining the leather molds are made of laminated MDFs. To prepare a big stock like what I needed, you'll need to work very fast: applying the glue fast, using a putty knife or a stick to even out the glue, and clamping the whole piece as soon as you glue all the layers.
To make the glueing stronger, I used 80 grit sandpaper to make the surfaces of the MDF boards rougher first. The laminated stocks were left to set for at least 24 hours before I started to machine them.
Step 5: CNC Machining Molds
I used Inventor HSM to generate the toolpaths and the machining happened on the DMS 5-axis CNC machine at Pier 9 workshop. MDF is very easy to machine: a roughing path and a finishing path (stepover 0.05 inch) will give you a pretty good finish. Machining MDF will generate a lot of dust, so using dust collector and wearing a mask are quite necessary.
I machined 6 mold parts (3 pairs of male and female plugs) all together. I speckled some cracks between different layers of MDFs and sanded very mildly.
Step 6: Wet Forming Leather
To form leather in shape, the first step is to choose the right kind of leather. There're two major categories of leather: vegetable tanned leather and chrome tanned leather. Only vegetable tanned leather will form, and it looks pale/pinkish when you purchase it. There're a wide range of finishes you can do to vegetable tanned leather, like staining, dyeing and painting, so always buy the raw skin like vegetable tanned leather instead of colored ones even if they tell you it's vegetable tanned.
Vegetable tanned leather come in different thicknesses. Thicker leather, after wet forming, will become much harder than thinner leather. For this project I used a variety of 5-7oz leather.
To wet leather, soak it in room-temperature or slightly warmer water for 10 minutes (this time is not definite). Massage and stretch the leather a little bit in the water. Don't use hot water cause the leather might shrink and become brittle after dried.
I used plastic wrap over the molds to make sure water wouldn't seep into them. Put a big enough wet leather piece between the male and female plugs, press them together, smooth the wrinkles on the edges, and then clamp the whole thing tightly. The wetted leather can take a few days to dry completely.
Step 7: Luggage Construction Planning
Any sewing project requires careful planning so that no rough edges/seams will be shown in the final result. To build a luggage from scratch is no easy task. I made very detailed planning about each individual pieces I'll need, how to connect different components (sewing or hardware or glue, add seam allowance, etc.), and the order of treating leather (for example, you can't dye the leather properly once you burnish the edges using gum tragacanth, the different leather treatments much be in order). The planning also included all the hardware decisions, and how to incorporate their dimensions and restrictions into the overall design.
Step 8: Preparing Individual Components
Each piece of leather is cut, beveled, punched holes, dyed, finished with a gloss coat, and edge-burnished (in the previous order). All pieces were pre-assembled before dyeing to make sure the sewing holes align. It was a very labor intensive process but it was crucial to the accurate assembling of the luggages.
Dyeing leather is pretty straightforward. I used Eco-Flo water stain from Tandy Leather, and the instructions are easy to follow. One thing to keep in mind is that vegetable leather get darker when it's wet, and when you are applying the dye, you're wetting the leather at the same time, so the color you see directly is a much darker / sometimes dirtier color than it will look once dried. Don't panic if you don't see the desired color immediately. You can also get a richer/more saturated color by applying a second coat.
The challenge of working with leather, a natural material, is that it will never be perfect. Besides the scars and wrinkles on animal skins, different pieces of leather might absorb dye differently, so it's very important to choose similar quality leather pieces for the same project. If vegetable tanned leather is exposed to sun light, its color will become darker/more pinkish and tends to make the dye color less saturated.
I dyed the sewing threads as well so that they match the color of the leather.
Step 9: Final Assembly
Once I had all the components ready, I started the labor-intensive hand-sewing process. To choose hand-sewing instead of machine-sewing is an aesthetic choice as well as a technical one: the kind of geometries for the suitcases makes it hard to sew on a normal industrial sewing machine.
The sides of the suitcases were reinforced with book boards. The lining was black silk and leather combined. All hardwares - zippers, luggage corners, handle d-rings, and rivets - are brass in glossy finish.
Step 10: Glamour Shots
Overall I'm pretty happy with the finished suitcases. The silhouette of the body is not too obscure nor too obvious, and with all the color and brass hardwares, the suitcases have a strong sensual quality to them. The body is "encased", yet its energy and sensuality is freed.
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