metal laminate
Go to Ace hardware or your local hardware supplier and they will have metal laminates to choose from that most of the time have to get ordered in, but never took too long. I liked Wilsonart the best. A few things you should know:
1. If doing exterior work ORDER WITHOUT phenolic backer as this is a paper product used to make cheaper adhsives work better. This is a paper product and will swell and could cause issues downt the road.
2. Mount a good perminate 3M sheet adhesive (9786?) with a laminator and then use the laminator to mount the laminate, you get one chance since pulling off the metal will bend it and ruin the finish. CLEAN EVERYTHING FIRST
3. When using any laminate be careful about nesting your letters / logos in the job file, once installed a letter cut out of place to have better yield might look out of place on the wall becuase how it catches the light or the pattern not being consitant. Worst case: (I once had a bonehead that rotated a letter 90" when cutting brushed metal and didn't notice until I was 30' in the air installing)
4. Mask the face with a good med. tac application tape to potect during production.
5. Use a good router bit and I always liked to do two passes one thru the laminate + .125" of substrate and then secound pass to cut all the way thru.