My cousin is a begining taxidermist. Im having him mount a deer but i didnt get a neck measurement before caping. I know when we measured the cape flat it was around 7.5inches which is 15 in circumfrence but i dont know how to compensate for the tightness.I assume it's important for ordering the underpiece. He said he would figure it out. He has only mounted a few but is a perfectionist and does a good job. He does a lot of waterfowl.

If he is a perfectionist then yes he will "figure it out." If the cape is to be tanned (as it should be) he should measure it after tanning. A measurement of the carcass is really not needed.

To measure a tanned, rehydrated, restretched long incision cape, lay it out on the floor hair side down, do not over stretch it, measure across the cape three inches down from the ear butts. This measurement is the most useful when ordering a form. You may also measure down from that at the widest point of the neck swell. The company you are buying the form from will have instructions in their catalog.

Thank you.