Back when I was a courier, I made myself a big hi-vis badge for my chic black Timbuk2 bag. It was a great success as I haven't been hit by any absent minded motorists yet, which i attribute to being highly visible, as well as taking care - there's no substitute for safe cycling. The badges are sewn together from scraps of hi-vis vests, which seem to be abundant these days. I then sew them onto the outdoor skin of the bag, taking care not to penetrate the waterproof inner. You can also use velcro to make the badge detachable.
I've made a dew of these to different designs, so forgive the mish-mash of photos in this instructable.
I make these up to order at www.zero-waste.co.uk
Step 1: What You Need
1 x hi-vis vest, of the sort worn by roadworkers, and now, any kind of pedestrian or cyclist prone to being hit by a vehicle! These cost about £5, or much less in bulk or from an industrial supplier such as this one. Most workplaces could get you some.
1 x reel of thick thread, preferably synthetic and a needle.
A pair of scissors, pen or chalk and a ruler and square.
This .svg layout sheet
Some Dress pins
A sewing machine.
Optionally: sew-on velcro. (approx. 1m per badge)
UPDATE - Have had to remove the .svg file link from here as apparently it never worked! See the link above for the .svg layouts.
Step 2: Choose a Design and Mark Out
Choose a design from the layout sheet, and print out at full size if possible. Generally the reflective strips on a hi-vis vest are 45mm wide, and the layouts have assumed this. Check yours are the same, and scale the layout sheet up or down accordingly.
Marking out is the trickiest bit, as one has to assess how best to cut up the vest. There's no real formula for this, I try to make use of the mesh and reflective strip as it is such that the minimum number of cuts and joins are required. Work out the best strategy on the paper by drawing on lines for the joins. You will want to add on 10mm around all the edges to allow for seams. Measure the dimensions, add on your 10mm and mark out on the vest using a pen/chalk and a ruler and square.
Step 3: Cut Out and Do a Dry Run
Cut out all your parts and lay them out as you intend to assemble them to check that it is correct.
Step 4: Assemble
Work out what order will be best to assemble all the seams. Take the pieces for the first seam, place them together facing each other and pin them together near the edge to be seamed (3-5mm from the edge). Then sew with a straight stitch at 10mm from the edge with the sewing machine. Tie off well.
Continue in this fashion to assemble the whole badge. This stage takes a while and is very methodical, so be patient and don't rush.
Step 5: Hem the Outside Edge
Once the whole thing is assembled and you are happy, hem the outside edge by folding at 10mm from the edge and pinning, then machine sewing.
At this point, if you would like the badge to be easily removable, sew on some velcro. I would put the hook side on the badge so that the bag or clothing remains soft when the badge is not attached. It is best to affix velcro all around the perimeter of the badge if possible to reduce sagging.
Step 6: Attach to the Bag or Clothing
This stage will probably need to be done by hand. If attaching to a courier bag, you want to only sew through the outer nylon so as not to damage the waterproof inner lining. This lining is pretty tough and separate from the outer so one can avoid it by tugging the outer once the needle is first inserted and being gentle, pulling back if the needle tip hits the inner.
I pin on the badge or velcro strips and use a backstitch or a zig zag running stitch around the edge. Be sure to tie off securely. Now is the time to add a label if you like, which looks quite good on the reflective grey strip material (see pic). For the velcro option, the method is all the same, but just sew on the looped velcro.