Before using the line, apply powder to the area you want to mark. Then pull the line along the marking. It should be stretched between two opposite points on the wall. Lay the bricks closely one after another along the line. Do not mortar the joints between them. For perimeter walls, start by setting the corners. Make sure each corner brick is rotated 90° relative to the others. It is recommended to wear a mask and gloves when working with this powder, as it contains hazardous silicon dioxide. If inhaled or in contact with skin, immediately rinse the affected area for 15 minutes. If irritation persists, seek medical attention immediately.