For the fabric cube we use the seam below. Fold the two peaces of fabric and sew them together (see cross section). This provides a good airtight seam.
Below you see our entrance-tunnel-design. We have attached a tunnel to the blue inflatable cube. We use the air-conditioning system to inflate de cube. At the end of the tunnel you see a lead cord that prevents the tunnel from being blown open by the air pressure in the cube.
With this tunnel entrance you can enter the inflatable without deflating the cube.
This Velcro entrance works really well as long as you don't make the cut too big (80 cm is the maximum) and you have enough air pressure. We tested it on the blue cube.
When you enter the cube it deflates a bit, but once you're indoors it restores again.
The Amsterdam Biennale 2009 is part of the Mediamatic Travel Project.