Mamma Ro dinnerware is a beautiful Italian hand-crafted ceramic tableware line that is available in rich colors, each with slight variations in appearance that are a mark in unique craftsmanship by individual artisans. Mamma Ro's unique red sometimes experiences an extraordinary occurrence after the initial washing. Raised white lines or specks may appear on part or all of the piece. These can be simply wiped away with a damp cloth or repeat washed 2 to 3 times as necessary. These lines will disappear after a few washings never to return. This happens as a result of a slightly different firing condition at the factory and does not always occur. The white substance is a mineral component of the glaze and it is not considered harmful. The vibrant colors are meant to mix and match as you may choose. The squares are meant to mix with the more traditional round pieces, or to be used alone or as serving pieces. ProductCharacteristics: Cleaning & Care: Handwash recommended, not microwave-safe. Origin: Italy Material: Ceramic Size/Capacity: Set of 2/16-oz. Dimensions: Diameter: 6-in./Height: 3-in.