Clear, Blue or pink glass adhesive stones for your adhesive drop.
Colour is usually clear but will vary in shipment.
Be sure only 1 drop of adhesive is on your adhesive stone at any one time. As numerous dried up drops can affect the current drop you are working with.
Do not let adhesive drops build up.
To clean use a cotton round with a small amount of acetone.
To keep the stone as clean as possible either use adhesive stickers, or lint free paper tape as your strip to place a glue drop on.