My understanding is many of the lower denomination notes, which bore the brunt of wear and tear, like Silver Certificates, exhibit this look. This bill was printed by the BEP in Washington, D.C., c.1934, for distribution to the FRB's district in Philadelphia, PA. [The BEP also printed larger denominations such as $500 - McKinley, $1000 - Cleveland, $10,000 - Chase [and $10,000 - Wilson, for dedicated, inter-FRB use between the twelve districts in the nation.]
Considerations in grading are many but are centered primarily on age, paper quality (exeptionally crisp versus worn out used bills; with little or no folding, holes, staining) and scarcity. Obviously, the older notes withdrawn from circulation after being forwarded to the FRB, and then, on to Washington, D.C., command the highest premiums. Their respective availability gets smaller or remains the same with each passing year. Price, as always, is predicated on demand.