10% OFF chalk style on blackboard for sales promotion

Illustration of "10% OFF" with a white chalk effect on a textured black background. Predominantly black and white, with gray tones in the chalk shading. Large "10%" numbers and the word "OFF" in uppercase letters, surrounded by a rectangular outline and decorative leaf and swirl details, all with strokes mimicking chalk. Centered and balanced composition, direct and promotional, with a vintage and handcrafted atmosphere, ideal for marketing campaigns or special offers.