the smallest details; every dot and stroke
A yojijukugo used to emphasize meticulous attention to detail, often in the negative pattern 一点一画もおろそかにしない (not neglecting even the smallest detail).
See also: 一点一画もおろそかにしない
He is a craftsman who does not neglect even the smallest detail.
契約書の作成には一点一画もおろそかにできない。
When drafting a contract, you cannot afford to overlook the slightest detail.