pt or px for specifying border-width for print

Question

should i use pt or px when specifying border-width in css for media print?

i basically just want hairlines

Answer 1

for hairlines use just px

Answer 2

For print you should use pt, as it's an absolute unit not based on the resolution of the media.

Answer 3

In general you should use points or em's in place of pixels when possible. The reason is that points and ems both scale with the users' resolution or zoom setting where pixels do not. On many larger, high definition or wide screen monitors individual pixels are too small to be reliably useful for placement.