Created attachment 8857769 [details] hr test firefox safari When we use border to created a dashed hr, the border is drawn unevenly around the box, creating a wavy effect, not beautiful to the eye. This issue happens only for borders at 1px. When the width is larger the drawing is regular and evenly spaced out. Tested with Firefox Nightly 55.0a1 (2017-04-10) (64-bit) Created a test case http://codepen.io/webcompat/pen/VbwGaW This is a spin-off of the Webcompat issue https://webcompat.com/issues/5616 Simple markup to reproduce <hr style="width: 200px; border-width: 1px; border-style: dashed;"> Screenshot attached. Firefox on the left, Safari on the right.