I was doing some research and I found a resource that I thought the folks here might be interested in: a wood hardness chart.
http://workshoppages.com/WS/Misc/Wood-Hardness-Chart.pdf
I’ve been using it to compare the easel settings for different types of wood.
Bah. No poplar.
I’ve used this one.
http://tinytimbers.com/janka.htm
Poplar is around 550 on the Janka scale, very soft in comparison to other North American hardwoods. It behaves in my experience like pine but with a tighter grain structure. If you are using easel settings I think you could start with that in mind.
Blair