Messenger Bag Prototype

This post is a little different than my usual “info about a kind of leather” but I thought I’d share a brief post about a bag I’m developing.  The prototyping process and what goes into the design process.

I’ve been making “box” corner totes for a few years now and last year we came up with a 3-piece design that we really liked that allows for interesting types of combos with the leather.

The inspiration:


After a fellow crafter suggested that the design could be adapted into a back pack, I started to think about other ways to make the “theme” into other bags.  I’ve been dying to make a messenger bag for years but we’ve never really had the time to work up a design.  Additionally this design had the possibility of being something new and different.

Working out the changes to the pattern:

The first step was adapting the pattern.  Tote bags look great if they get wide at the top but a messenger bag needs to keep a more or less rectangular profile.   This meant that the middle piece needed to be a trapezoid, that narrowed to roughly the same width as my bottom seam.  My first attempt came out too narrow and honestly looked more like a backpack:


The flap also came out wildly too long and in the above picture I’ve actually cut it back and shaped it.

Strap attachment issues:

The next pattern came out much better, but when I went to attach a strap I noticed a problem:  The flap, which originally had a much more rectangular shape didn’t allow for the handle/ring attachment I had planned.


Instead of starting fresh, I cut the already sewn strap to allow for the strap attachment:


Now we had the general design of the bag:


Another test of the pattern:

Next step was to draw the pattern out for the strap and then test it again.  To save a little sewing and gluing time I drew the pattern out a one piece:


I found a thinner leather and we sewed the design and added straps:


The leather was a little thinner than ideal but the strap attachment worked.

3-piece Prototype:

Now to try it as 3 pieces and add a couple pockets while we’re at it:


We also decided to try adding a top handle:


Final Prototype (for now):


Complete with front and back pockets and a strap that’s absurdly too long for any normal human (but I didn’t want it too short).


What’s next?

After carrying this prototype around at a convention this weekend I got lots of compliments but was also able to see some things I’ll change before this ever hits production.  The top handle is slightly too far forward and a little big. The back pocket is about 1″ to narrow to fit an Ipad with a case, both easy fixes.

I’m also thinking about change the flap shape to more echo the shield on the front and reduce the “lobes.” I think the pattern in the top right of the picture below may be the way I go.


So this is still a work in progress, but I thought I’d share the process and some of the lessons learned.  I’d also love any input you’d like to give on this design.


3 thoughts on “Messenger Bag Prototype

  1. Great bag, I appreciate the two tone look, front strap design and double stitched long strap. I’ve been advised to accent the rivets with stitching to the top handles, those rivets have different pressure points than the ones attached at side, pulling straight up can wear over time creating a weak point.


  2. Great insight as always. Thanks for the peak into the many steps and iterations. Many customers don’t know the amount of time it takes to design.


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