There are many factors that impact the results of a blasting process. These include the blasting pressure, the blasting angle, distance from the surface, and, most importantly, the abrasive blasting media being used.
Different blasting media will produce very different types of finishes. In the picture on the left, you can see two coupons blasted with Glass Beads. Glass Beads produce a peened surface finish. The one on the left is a 20/30 Coarse grade and the peening marks are clear. As a larger Glass Bead, the finish is also brighter. The other coupon was blasted with a 100/170 Medium-Fine grade. The finish is much smoother and also more a satin-matte finish.
The picture on the right shows the same Glass Bead – 20/30 Coarse blasted coupon next to a coupon blasted with a similar particle size Aluminum Oxide Grit – 36 Mesh. The difference is stark showing the coarsely peened finish on the left and the rough etch of the Aluminum Oxide Grit blasted surface. The hardness and angularity of the Aluminum Oxide removes much more metal to leave the rough surface finish.