If specimens are allowed to dry out or become brittle, they may shatter when being pinned. Dry specimens can be made soft and pliable again by placing them in a relaxing chamber for 1 or 2 days. To make a relaxing chamber, place 1 to 2 inches of clean sand or sawdust in the bottom of a large, airtight jar. The jar must be large enough to allow small dishes to be placed inside, and must have a screw type or other lid to create airtight conditions inside the bottle. Saturate the sand with clean water and add a few drops of carbolic acid (sold at most drug stores) to prevent mold growth. Place the specimens in shallow, open containers on the bottom of the jar, and fit the lid tightly on the relaxing chamber. Amount of relaxing time needed varies with the size of the insect and how dry it is when first introduced. Retrieve and mount specimens as soon as they are pliable enough to pin easily, but remember that they can be ruined if left in a relaxing jar too long. Relaxing the wings of dry butterflies and moths is essential to allow them to be properly spread.

The relaxing chamber should be used for emergencies, not as a general practice. It is always best to pin specimens within a few hours after collection and avoid the need for relaxing chambers.