If your amp has loose, sagging grill cloth there is an easy quick-fix to tighten it back up to be factory fresh. This remedy applies to the plastic type grill cloth typically found on Fender type amps. First remove the speakers from the amp and then remove the baffle. Then take a hair dryer or if you have experience, a heat gun and blow the warm air evenly over the entire baffle. The heat will tighten the grill and the sag will disappear! Be careful not to get too close to the grill especially with a heat gun. Use the heat gun on low heat settings and keep both the hair dryer and heat gun about 12 inches away from the baffle. Go slowly and check the grill during the process. If the grill feels too hot let it cool down for a moment and continue until you get the desired result. For amps with cane type grills such as a Mesa/Boogie or Marshall there is a similar procedure. Again remove the speakers and baffle from the amp. Get a spray bottle and fill it with water. Spray the grill evenly until it is saturated but not so much that water is dripping and running off of it. Just saturate the cane grill. Next repeat the same procedure as above with the hair dryer or heat gun. You can use more heat with the cane material and it will actually respond better. Again check the cane grill as you go along. Another method is in warm climates or summer months you can put the baffle outside in the direct sunlight. There will be enough heat to tighten it back up like new. Using heat on cloth grill’s as used on Vox type amps will not work. There is completely different repair and the grill actually has to be re-installed to get it to be tight again.