Using a burnishing plate is the best way to check your clipper blades after sharpening. Burnishing both comb and cutter to show there is contact at the tips for your quality control check.
The burnish should show as a darker area with a different reflection than the unburnished area. The contact should start at the very tips of the teeth and come down about ¼ of the teeth. A straight across pattern representing equal tooth contact is the best. If any teeth do not show contact at the tips the blade should be re-sharpened.