I'm looking for the information--I'll send it soon. Thanks!!

Grout was Bostik Classic Bone.

Thank you so much for finding the information! Really awesome work with the Heath tiles, especially with your choice to stack the 3x12 tiles. Also, great to hear that you used a polymer and it yielded fantastic a result. Thanks again!

Susan, wanted to write thank you again for the advice! We installed our stacked 3x12 Heath Robin's Egg tiles and used the Bostik classic bone. It turned out beautiful. We thank you for the advice and inspiration!

@joe131 do you have pictures of your tile work?