Using a large utility brush, paint your wooden plaque with black chalkboard paint. Let dry completely before painting a second coat.
After your second coat of chalkboard paint is completely dry, condition your chalkboard by rubbing the entire surface with a piece of chalk. Wipe away excess with a dry paper towel before proceeding to the next step.
To stencil/silkscreen "spoooooky treats," use the Striped Alphabet Adhesive Silkscreen and the Erasable Liquid Chalk. Cut apart the letters to spell your words. Remove your silkscreen and lightly pounce the erasable liquid chalk over your silkscreen.
Repeat the above steps to spell "Happy Halloween" with the Bodoni Alphabet Adhesive Silkscreen.
To finish your craft, add freehand details (like an arrow or a tombstone outline) with a piece of chalk.