4 oz clear glass boston round bottles paired with black metal foil lined caps are top choices for storing strong components. The clear glass boston round bottles are impermeable, for not being affected by the products stored within, while also not altering the composition of ingredients. Black metal caps include foil liners providing resistances to hydro carbonates, oils, ketones, and alcohols. Select these boston round bottles with metal caps for packaging hobby products, including paint cleaners, liquid adhesives, and more.