String instruments are marvels of art and science, loved for hundreds of years by amateurs and professionals alike. However, no matter the level of familiarity, anyone handling a string instrument must be aware of what may damage it, and how to avoid these situations. Otherwise, disaster can (and often will) ensue. For the purpose of this article, "string instruments" will refer to violins, violas, cellos, and basses.

The most common causes of damage to string instruments are as follows:

• Extreme temperatures

• Too much or too little moisture

• Sudden impacts

Any one of these factors can cause the instrument damage. At best, an intense tuning session will be required the next time it is played. At worst, the wood can begin to warp or crack, and the joints of the instrument may come apart. The remainder of this article will address each of these factors and what can be done to prevent damage.

1. Avoiding extreme temperatures

To hold instruments together, many luthiers use a glue that is solid at room temperature but softens in boiling water.¹ This means that exposing the instrument to higher temperatures will cause the glue to soften, and in this case, the hundreds of pounds of pressure on the joints of the instrument caused by the strings will warp the wood. Avoid leaving instruments in a hot car, direct sunlight, or next to a vent while the heat is on.

On the other end of the spectrum, wood contracts in colder temperatures, and will expand quickly enough to warp or crack if heated from those temperatures too suddenly.² If leaving the instrument in a cold place such as a car, anywhere outdoors in cold weather, or in a cold basement can be avoided, that will help prevent such a scenario. If this cannot be avoided, a padded case will help insulate the instrument and protect against temperature changes. Wrapping the case in blankets and towels during the change to the warmer location and keeping it wrapped until it warms up will work in a pinch.³

Where cases for violins and violas are concerned, if extreme temperatures are a serious issue, non-suspension cases offer increased insulation compared to other types of cases. The foam interiors of these cases fit snugly to the instrument and slow the change of temperature inside the case.4

2. Achieving ideal humidity

Acoustic string instruments are made of wood, which is a porous material. It readily absorbs moisture from the air around it, and releases that moisture back into the air in dry conditions. This causes expansion and contraction similar to that seen in temperature changes. Museums solve this by keeping the humidity consistent all the time, but that is not very practical for most musicians.

There are a couple of different solutions to this issue. One is to keep the room the instrument is stored in at a consistent 40%-60% humidity using a humidifier or dehumidifier. If the instrument must be removed from this room for a rehearsal, lesson, or performance, return it to this controlled environment as soon as possible.

The other solution is to put a humidifier in the instrument's case. Case humidifiers can be found at most instrument supply stores, online and brick-and-mortar, for a variety of budgets. This works well for those living in dryer climates, but will not help much in higher humidity.⁵ Where cases are concerned, weatherproofing will help keep the interior of the case consistent in humidity.⁶

3. Protecting from impacts

Simple accidents can cause severe damage to string instruments, but many of them can be prevented. Always put the instrument away properly when not in use, either in its case (securely closed) or on a sturdy stand. Many accidents occur as a result of picking up a closed (but not zipped or latched) case, and out tumbles the instrument.⁷ Make sure all straps, ties, zippers, and latches are secured, including those for the bow(s). Also make sure there are no items — rosin, pencils, etc. — on top of the instrument when the case is closed, as this can cause damage as well.

A good quality case will also help protect the instrument. Fiberglass, carbon fiber, and Kevlar are popular materials for their durability and light weight, but tend to be much more expensive. Wood is durable, but much heavier. Many cases are all foam with a fabric covering.⁸ Whatever the exterior material, for violins and violas, a suspension-style case will offer excellent protection against impact. This style of case, usually made of foam, cradles the instrument with a small amount of space between the instrument and the case interior, absorbing much of the shock of an impact before it can reach the instrument.

Padded covers, made to slip over the main case, offer extra shock-absorbing and sometimes weatherproofing protection. For cellos and basses, padded "soft" cases in a similar style are common, but offer little to no shock resistance and protect mostly against cosmetic damage. Molded fiberglass or carbon fiber cases offer much better protection against impact. Many of these cases feature wheels for easy transport, which can be a tremendous help in avoiding accidents with such a large and heavy instrument, especially in situations where it must be carried over long distances.

When it comes to protecting an instrument, knowledge is power. Know the environment, know the instrument, and protecting your investment, heirloom, or best friend will be as simple as taking a little extra care to make sure all is well.