The band resizing process necessitates removing or adding small amounts of its metal, depending upon the distinctions between the size bought and the new one requested. Consequently, your engagement ring may be slightly thinner or thicker after resizing.
These are small changes, which are often imperceptible. There is a chance that after it is resized, jewelry makers may clean and polish it before returning, so that would add to its looks as well. So that would be a good option to upgrade the engagement rings on a special occasion, like an anniversary.
It is good to have the option of having a ring band resized as per requirement. When on it, make it a point to order the correct ring size to avoid any further confusions. However, note that not all rings can be resized; some owing to their design. For instance, diamond eternity rings with a number of gems, rings with ornate or milgrain designs, or those with alternative metals such as stainless steel or tungsten, cannot be resized.