What is the difference between pulpboard and paper coasters?

‘Pulpboard’ coasters

are the most common bar coasters you’ll see with the branding of a beer or liquor brand. They’re made of recycled pulp and are very absorbent. They come in three common weights; 

Lightweight: 35pt or 40pt

Mediumweight: 55pt or 60pt

Heavyweight: 80pt

‘Paper’ coasters'

is likely another term you could use to refer to pulpboard coasters. Or, you could consider them to be a very lightweight paper sheet that serves as a lower cost coaster. These aren’t absorbent and usually need to be tossed after 1-2 uses. If a lightweight coaster is 35pt, you could consider a paper coaster to be around 10pt thickness.