mediumwhat am-i

Fill my bucket, spill my bucket, Over a plane of snow. Black the track as I look back, My footsteps talk but make no sound. What am I?
Common Wrong Answers
“A snow shovel”
A snow shovel is used to move snow rather than leaving a mark on it. The riddle describes the act of filling and spilling, which aligns more with a pen that 'fills' with ink and 'spills' it onto paper.
“A paintbrush”
While a paintbrush can create marks, it does not 'spill' in the same manner as a pen does with ink. The riddle specifically hints at a silent process which aligns with a pen's writing rather than the more audible action of painting.
“A footprint”
Footprints are the result of walking on snow and do not 'fill' or 'spill' anything. The riddle focuses on an object that creates a mark without sound, which is characteristic of a pen.