SPF is the gold standard for framing lumber.  It is lightweight, strong and easy to cut and nail.  It is a favorite among carpenters and homebuilders.  

SPF is available in three different grades:

4-Square SPF - The absolute best appearance and grade is available by special order.  This is a structural #2 grade with a strict limitation on wane.  This lumber is the absolute best looking lumber.  98% wane free with occasional pencil wane.  4-Square SPF bears a #2-grade stamp.  Blue stain is allowed and knot size will be the same as with #2&btr.

MSR 1650 - A combination of strength and appearance is available by special order.  Machine Stress-Rated Lumber (MSR) is dimension lumber that has been evaluated by mechanical stress-rating equipment. The stress-rating equipment measures the stiffness of the material and sorts it into various classes.  MSR 1650 is also graded for appearance and has a #1 face.  MSR 1650 is lumber graded for both fiber quality and appearance.  It is stronger than #2&btr, and has a # 1-grade appearance.  We recommend MSR 1650 for customers looking for reliable and consistent strength, and for those that are looking for something a notch above #2&btr's appearance.  

#2&Btr - This standard cost-effective grade is the workhorse of framing lumber.  It' naturally soft white wood is easy to cut and nail, making it a favorite among carpenters.  We recommend #2&btr for customers who are looking for the most cost-effective lumber for framing which is why we stock this grade.  It is not an appearance grade board and will have bark, wane, and blue stain.  Wane is allowed up to 1/3 of the thickness and 1/3 of width for the full length of the board.