26 BULLETIN 1485, U. S. DEPARTMENT OF AGRICULTURE 
By Sulphate Process 
Reduces readily. 
Unbleached pulp: Strong, of fine texture. 
Yields: 45 to 50 per cent of strong pulp. 
Bleaching properties probably similar to those of white spruce. 
Uses to which pulp is suited: High-grade kraft wrapping papers and fiber 
board. 
By Mechanical Process 
Reduces readily. 
Pulp: Of excellent color and standard strength. 
Power required: Comparable to that for white spruce. 
Uses to which pulp is suited : Practically all uses requiring ground wood. 
Blue Spruce [Picea pungens, formerly P. parrayna) 
Other names in use. — Parry's spruce, white spruce, silver spruce, and Colorado 
blue spruce. 
Range. — Central Rocky Mountain region — Colorado, eastern Utah, southern 
and northwestern Wyoming, and northern New Mexico and Arizona. 
Oven-dry weight per cubic foot, green volume. — 23 pounds. 
Fiber length. — 2.8 mm. 
By Sulphite Process 
Reduces readily. 
Unbleached pulp: Strong, of fine texture and excellent color; bleaches easily 
to excellent white. 
Yields: 45 to 50 per cent. 
Bleach required: 10 to 20 per cent. 
Uses to which pulp is suited: News, wrapping, book, high-grade printing, and 
bond papers. 
By Sulphate Process 
Reduces readily. 
Unbleached pulp: Strong, of fine texture. 
Yields: 45 to 50 per cent of strong pulp; 38 to 43 per cent of pulp for bleaching. 
Bleach required: 20 to 30 per cent in one stage, or 15 to 20 per cent in two stages. 
Uses to which pulp is suited: High-grade kraft wrapping papers and fiber 
board. 
By Mechanical Process 
Reduces readily. 
Pulp: Of excellent color and standard strength. 
Power required: Comparable to that for white spruce. 
Uses to which pulp is suited: Practically all uses requiring ground wood. 
Engelmann Spruce (Picea engelmannii) 
Other names in use. — White spruce, balsam, mountain spruce, and silver spruce. 
Range. — From southeastern and northern Arizona and southern New Mexico 
northward through the Rocky Mountain region to British Columbia, and west- 
ward to the eastern slopes of the. Cascade Mountains in Oregon and Washington. 
Oven-dry weight per cubic foot, green volume. — 21 pounds, 
Fiber length. — 3 mm. 
By Sulphite Process 
Reduces readily. 
Unbleached pulp: Strong, of fine texture and excellent color; bleaches easily 
to excellent white. 
Yields: 45 to 50 per cent. 
Bleach required: 10 to 20 per cent. 
'Uses to which pulp is suited: News, wrapping, book, high-grade printing, and 
bond papers. 
By Sulphate Process 
Reduces readily. 
Unbleached pulp: Strong, of fine texture. 
Yields: 45 to 50 per cent of strong pulp. 
Bleaching properties probably similar to those of white spruce. 
