Introduction: Laser Cut Leather Flask

About: Former long time designer at Instructables. I have a degree in fashion design and like to sew, get crafty, and attempt to use power tools.

A good friend gave me a leather covered flask as a gift years ago, and over time the existing leather started peeling off and looked a bit worse for wear. Time for a revamp! I have been wanting to do more laser cutting and work more with leather, so this seemed like the perfect opportunity to do both.

As I used a flask which had an existing cover, it had a nice inset surface which made application easy and framed the cover (although the double layer meant it was no longer flush). However a cover like this could be added to any flask, one would just need to be extra careful when glueing to achieve a clean edge.

Step 1: Prep the File

There were several stages to preparing the file.

First I measured the flask to determine the dimensions. I messed this up big time the first time around by measuring the flask without accounting for the first layer of leather, thinking it wouldn't be a huge difference. Wrong! Measure carefully. For thin leathers make your file about 1/8" - 1/4" shorter around to accommodate for stretch. Once you have an artwork size, the computer work can start. Your process may be different, but here are the steps I took in Photoshop/Illustrator CC:

Photoshop

  • Found a black and white low res image online to use as a base
  • Brought it into photoshop on an art board the correct size
  • Duplicated the image side by side, then hand drew in a seam in likeness to the existing pattern
  • Selected all black in the file (Select > Color Range), and contracted the selection so the lines between what would get laser cut out were thicker (Select > Modify > Contract)
  • Pasted to a new layer, then cleaned it up with a lot of hand drawing. This included removing pieces along the edges which looked too small by clumping them into shapes next to them, and general cleaning up of the edges to be clean and un-pixelated.
  • Once the image looks crisp and clean, save as a jpg and open in Illustrator

Illustrator

  • Object > Image Trace > Make - will trace the image, but won't show the path
  • Object > Image Trace > Expand - breaks out the path
  • Delete the solid rectangle container to leave only the art we care about
  • Clean it up - despite importing a smooth file, there were still jagged edges here and there. There is probably an easier way to go about this, but I fixed them by hand, as simplify path didn't really do the trick.
  • Add outer container and stitching holes (mine are .03", 1/8" apart)

Step 2: Clean the Flask

There was quite a bit of residue on the flask, so first I cleaned it up with some goo gone (any similar solvent will work). A cotton ball works best, which I didn't happen to have handy when taking this photo. Rinse with soap and water when finished.

Step 3: Cut Base Layer

I used my paper pattern as a base for height, and cut a strip to fit the flask as a base layer. Double check this layer fits, then check your laser cut pattern for size before hitting the laser cutter!

Step 4: Laser Cut the Leather

Time for lasers! I am very lucky to have access to a laser cutter. If you do not have access to one in your area through hacker spaces or shared workshops, Ponoko offers several colors of veg tanned leather, which will be much thicker than what I am using here but also more durable. You also can skip the laser cutting altogether and play with tooling and traditional leather working techniques for ornamentation. Check out our leather channel for ideas.

For those that do have access to a laser cutter, here are the settings I used on a 75 watt laser:

  • Speed: 60
  • Power: 20
  • Frequency: 500

Anyone who has done much laser cutting with leather knows that it stinks. Once the cutting is complete, your piece will have a fair amount of char that is unpleasant to smell and messy. Cleaning something this thin and delicate is difficult, but I did a light clean using a mildly damp toothbrush with the leather laid flat over a paper towel, working in gentle circles around the cut lines and rinsing the toothbrush often. A quick pass on both sides took care of the worst of it.

Step 5: Stitching

I'm not sure what this stitch is called, but I liked that it created a slightly angled stitch for a little more visual interest than a straight saddle stitch. This angle is created by laying down a length of string on the backside, and looping around it from the front in the same direction each time, keeping the tension at the back. In these images I doubled up the string for the front side, as it was a little too thin visually for my liking as a single strand. To begin I tied off the front and back strands to anchor the start, and stitched from there, tying off the ends when finished.

Once one side was complete I used nail polish to add strength to the knots before trimming the ends.

I proceeded the same way for the bottom, except that I used a much longer length of string in order to be able to lace up the opening as well. One could also use a third length of string for just the lacing, but I figured using the same length of string would provide less of a chance of unraveling over time.

In the last photo you will see the piece ready for application to the flask. All four corners are tied off, reinforced with nail polished, and trimmed, except for the two ends which will lace up the back.

Step 6: Glue It Down

Time for the moment of truth! The first time I did this, I didn't measure my outer layer well enough, and it didn't fit. This is AFTER doing all the hand stitching. Save yourself the trouble and make sure to double check that everything fits well before hand stitching or glueing anything.

Now that I knew I had two pieces that fit, I glued them down using Super 77. While it doesn't provide a super strong hold, the ability to reposition and apply evenly made it a good glue for this application. The back of the initial layer doesn't need to have a perfect seam, but it shouldn't overlap. Get it as close as possible.

For the laser cut layer, I found that starting at the back with a careful application of the first edge at center, and slowly applying around the flask until back at the seam line worked best. Mine required a bit of stretching to meet perfectly at the seam, so I made sure to stretch before applying to avoid any visible glue. Needing to reposition will result in a lot of visible residue, so apply with care and try to get it right the first time.

Step 7: Finishing

Now that everything was glued down nice and tight, I needed to peel it back up! It would have been better to tape the edges to prevent them from getting glued in the first place, but I didn't have that much foresight. I peeled up just the outer layer to expose the stitching holes, and laced it up. At the bottom I tied it off, applied nail polish to the knot, and trimmed the ends. Lastly I applied a small dab of E6000 to the top and bottom of the seam for reinforcement, as these areas will be the most prone to peeling and unravelling.

As an optional final step you can sponge on a coat of finishing liquid to add further protection. I used Eco-Flo Satin Shene, which although it is intended for veg tanned leather which mine is not, I figured it couldn't hurt. This flask is pretty fragile, so every bit of coating helps!

With that, the flask is complete! Be sure to post an "I Made It" comment with photos if you make your own!

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