The masking fluid Rubbel-Krepp Blue by Schmincke is a odorless masking liquid specifically designed for covering areas that should not be worked on across various painting surfaces. With a volume of 20 milliliters, this product is ideal for use on watercolor paper, smooth drawing cardboard, and similar surfaces. The application is straightforward with a cotton or wooden stick, as well as a writing or drawing pen, allowing for precise and controlled application. The blue color of the masking fluid ensures that the covered areas are clearly visible, making the work easier and providing a clean separation between the processed and untouched areas. This painting accessory is an essential tool for artists who value accuracy and cleanliness in their work.