Rings per inch

[Tree_Ninja]

  Hey all,

  It was difficult to find a true definition of Rings Per Inch as it is used commonly on this site.  When I calculate age of a tree with an increment borer or looking at the cookie I count every 2nd ring (count the darks or count the lights) to determine age as two rings equals one year of growth.

Is that how most folks on here calculate the RPI? Or do you count both light and dark rings. I only ask because 50 RPI in my mind is 50 years of growth=1".

Thanks in advance for clarification.

[Del the cat]

Yeah, you count the dark OR the light, not both.
Not that I bother very often, as counting 'em doesn't actually affect the wood!
There's a saying "You don't fatten a pig by weighing it!"
Del

[DC]

I just count the dark ones.

[Tree_Ninja]

I thought that was the case. I only have one yew around 50rpi, most of the others are 28-35.

Most of my OS is about 22-32. 

Meanwhile some of the 2nd growth douglas fir we are harvesting now is 60 years old and 25" diameter.

Really RPI is a statement of growth/age.  Thanks for clearing it up.

[burn em up chuck]

  light and dark= one growth year, light=early, dark=late. for osage higher percentage of dark to light is preferred.

                                                                                                       chuck

[loon]

some guy who made sinew backed compression pine bows said that it doesn't matter for compression pine, and that compression wood with much less rings/inch is way better than tension wood with more ring density?
I should make cable backed pine branch bows :| need to go to some forest with dead pine trees..