I am in the processing of building one right now and found a lot of helpful info from binky members and figured a lot out while making it. Bed Bath and Beyond has the black grids by Design-A-Cubes for $19.99, 17 grids in each box. Mine is going to be 4 grids x 2 x 5 so we got 3 boxes. Be prepared to use A LOT of zip ties!! We had to go back twice to get more, we ended up with 6 bags. I got mine from Wal-Mart: long ones, black, 100 count, $3.99/pack. Make sure your grids are facing the same way when you zip tie them together. We had overlapping problems and figured out this was our issue, no problems since! I recommend using a pliers to tighten the zip ties too, your hands get sore after awhile. Make sure the ends of your zip ties are all on the same side to prevent bunnies from running into them and poking themselves! I’m sure I’ll have more tips once we actually finish ours, it’s about half zip tied together so we have a long way to go! Good luck 