Yeah my other Whitcomb project has 3D square holes that fit etched parts perfectly. But there is the part thickness to worry about. A 3D grill would be about .016" thick and probably curl because of that.
Also do you know a way to upload a file to Shapeways and have it back in 2 hours>?
Speaking of that. My last Shapeways order... I choose the second UPS shipping option and the shipping was soooo much faster.