Step 1: Materials
ikea frame ($2.00/pair I think)
something to be a dry erase surface: dry erase self-adhesive sheets (shown), glossy white plasticky shrinky dink sheets, transparency sheets, glass, something like that (price varies)
cardboard or thin wood for extra backing
hammer and 1 cm hole punch
bubble wrap spacing template (attached pdf)
Update: use a cricut
Step 2: Trim acrylic sheet
This will allow you to expose a strip of bubble wrap alongside the whiteboard material.
Step 3: Optional: cover the acrylic sheet with a dry erase surface material
I went even further and punched out a line of 1 cm holes for the bubbles to line up into. That was quite difficult and took a few tries. I even went so far as to create a perfectly aligned template using Sketchup (see attached pdf on the materials page), which helped with the alignment a great deal. Update: this can be done much more easily with a cricut and the svg file provided on the materials page
Tape the dry erase material down on top of a magazine. Tape the template down over that. Line up the punch over the holes. Rap with the hammer two or three times to create a hole. Carry on like that for 14 holes in this case.
Step 4: Cut additional backing board for support
Using the paper insert of the Nyttja frame as a template, cut out a similarly sized rectangle from thin plywood - approximately 3mm thick. This will provide extra backing which makes it a little easier to snap the bubble wrap.