Hi there! I'm testing out the Product Variants feature found in the Shapeways Labs section and I believe it can become a very good normal feature for shop owners to use. Each model I make comes in 4 sizes: Small, Medium, Large, and EPIC. Unfortunately, due to the limitations of production technology, not all materials can be used for all sizes. For example, a small fairy that I created can be made in silver, while the epic sized version cannot be made in silver. Using the fairy model above, I experimented: 1. My default size for the fairy is small, Silver Material is available for use. 2. After pasting the Product Variants code in the description, I now have Medium, Large, and Epic sizes available for clicking. 3. The Epic sized fairy cannot use Silver Material. 4. I clicked on "Epic" size anyway just to see what would happen. 5. I ended up having the Epic sized fairy in my cart using its default material, which was set to the White Strong one. 6. I tried another experiment, this time I went back to the fairy. 7. I chose Glazed Ceramics Material which is available for both Small and Epic sizes. 8. I clicked on "Epic" size. 9. The Epic sized fairy went into my cart, but it still was set to use the default White Strong Material instead of the Glazed Ceramics that I chose. I can see some potential problems with the way Product Variants works now: 1. A customer goes into a shop and finds a nice item to buy. Its default material is Full Colored Sandstone. 2. The customer chooses a material that he wants the item to be made in, like Silver. 3. After reading the description, he finds out that he can buy the item in different sizes: Small, Medium, Large. 4. He decides to buy it in Large size and clicks. 5. The Large sized item goes into his cart but gets set back to the default Full Colored Sandstone Material. 6. The customer doesn't notice this and pays for the item. He only realizes the mistake at a later time, which is pretty inconvenient for him, the designer, and Shapeways. My Suggestions: In my opinion, although everyone should double check what it is they are paying for online, we cannot expect all of the customers to always do this. We have to make everything as easy and intuitive for the customers to buy what they need, exactly as they chose it. For the situation that I described above, I believe the solution is pretty simple. Instead of putting those Product Variants icons like Small, Medium, Large in the description area, we should instead have drop box list placed on top of the Materials options instead. The reason for this is that the available materials a certain item can be made with is dependent on its size as well. When we place place the Product Variants (in this case, size) above the materials list, we are suggesting to the shopper to choose a size first. When they choose a size, the materials list will change accordingly. The next natural flow of action is to choose the material, and since the system has already determined that the customer wants the item in Large size, the materials list will show the proper ones for that size. Here's my idea in a more visual form: Thanks for reading and I hope you implement some of my ideas.