The influence of shaking spray paint cans, prior to spraying, on the characteristics of the obtained paint coatings was studied. It was found that large variations in the characteristics of sprayed paint coatings can be obtained, depending on whether the cans were shaken before the spray was applied. Therefore, care should be taken in interpretation of the results obtained in comparison of paint when spray paints are involved. To account for the obtained results, the mechanism of spraying with unshaken spray cans was studied using both X-ray radiography of spray paints during spraying and simulated experiments with sand suspensions in water.