And I could not let that stand...: black plastic ribs? No way! I went to the first steel place here in town - they told me that they cannot cut 5mm strips. When I asked why, they looked at me funny. Obviously, they were not too bright. So off the the second steel place: No problem. 5mm means only that they cannot use their automatic stop of their cutter, but have to mark the 5mm by hand. That's all.