Yes probably a full cap or a bit more, you can see most of the top of my head is thin and the hair is longer so no way is half a cap going to work, cheap adjustable stamper from eBay, but I’m going to get a better one
Thanks for documenting this, @Brownbeaver . You mentioned the newer hairs were still thickening even though fewer were appearing. Have you taken the six-month photos you planned for October? We'd be interested to see how things compare with July, especially under similar lighting and with a similar hair length.