How to ensure the accuracy of the aluminum parts after processing the anodized ?

How to ensure the accuracy of the aluminum parts after processing the anodized?Most of the machined aluminum parts need to be made of anodes, and have different colors, such as: black, red, blue.Our engineers found that the aluminum parts anodize would have a size effect of 0.003 to 0.013mm on the size.This will seriously affect the precision of machined parts.We have taken an effective approach,1 in the cnc machining process to consider the size of the anode after the change, size increase or decrease 0.003 ~ 0.013mm.2. Directly with the appropriate size of the silicone plug plug hole, to prevent the anode during the aluminum parts of the impact. This method is widely accepted by customers.