I'm referring to "Silkspan" which is a tissue paper especially made for model airplane covering. Silk is a cloth and cannot usually replace Silkspan because silk requires much more dope thus coming out much heavier. Also, Silk has a strong pull when shrinking so it cannot be used on light weak structures. Silkspan used to be made in three different grades, one was very light for small models and the heaviest for big "gas" models. I do prefer the medium grade for general model covering.