60 durometer squeegees are the softest available, and are used for more delicate printing. A softer blade flexes more than a hard blade, and works best with thinner inks. 60 durometer squeegees also are great for high density printing since they allow a larger amount of ink to roll through the stencil.
70 durometer squeegees are a medium hardness, and are the most commonly used. A 70 durometer squeegee blade works well with almost any screen printing application, and is a great starter option for the beginning screen printer.
80 durometer squeegees are fairly hard, and are great for fine detail printing. They also work really with water based inks, and create a nice soft hand.
90 durometer squeegees are the stiffest available and are great for more intricate print jobs. 90 durometer screen printing squeegees are commonly used with process printing where fine detail is a must.