• Research and Development, Glaze, Model, Clay Body, Boston Valley Terra Cotta



Color development typically occurs concurrently to the work of the drafting department. R&D for glaze matching and/ or clay body development on a restoration project requires selection of a 12”x12” or larger control sample by the architect or building owner. This control sample must be cleaned with the same solution that will be used to clean the building. A new construction project can draw upon past Boston Valley Terra Cotta projects and other materials including paint colors, Pantone colors, fabric swatches, or other façade materials as a basis to start discussions about the glaze finish or clay body color.

Once Boston Valley has received this control sample, we will begin working with our in-house glaze recipes, minerals and stains to achieve an acceptable match to the glaze finish or custom clay body color. A 6” x 6” sample tile will be created for each test. Half of this tile will be sent to the individual who selected the control sample while the other half is retained for Boston Valley’s record. Should any modifications be requested, we will perform additional tests; should the tile be found acceptable, we will require a written record of approval. With hundreds of colors in our glaze library, Boston Valley’s R&D Department has a history of successful glaze development to draw upon for your restoration or new construction project.


Upon approval of glaze/clay body color and all drawings, most projects proceed to the model and mold shop. This department uses the shop drawings created for each individual restoration piece to produce a model of the unit. Because clay is formed wet but goes through a drying and firing process, the model must be made approximately 8% larger in all dimensions than the finished unit to account for the shrinkage that will occur. The model and mold shop uses different material such as plaster, Plasticine®, rubber, wood, and metal in their crafting of the model. Once the model has been approved, either by our in-house Q.C. process or a visiting project team, a 5 piece mold will be taken of the model. The number of units required for each block style determines how many molds are needed to complete the job. Once made, the molds are dried and then sent on to production. This department makes molds for use primarily in the hand pressing production of units but also for the RAM press and slip casting operations.