PLEASE NOTE - Our chalk markers work perfectly with bright and vivid colors on ALL non-porous surfaces. its recommended to try them first on small areas and always follow the cleaning instructions provided. NOT ALL CHALKBOARDS ARE SUITABLE FOR THE USE OF CHALK MARKERS. PLEASE TRY THE MARKERS ON SMALL AREAS FIRST TO AVOID RUINING YOUR BOARD.
If the chalk markers can not work on your blackboard, pls check if your blackboard is a non-porous surfaces.
If the chalk markers doesnt work , pls follow the steps: 1,Shake well with cap on & pointing up for 30s. 2,Press down and back 2-3 times until the ink flows. 3, Start having fun.
If you get a defective product, please feel free to send us a message anytime. we will respond to it promptly and send a new one to you.