Physical photographs can carry quite a bit of sentimental value, especially older photos that do not have a digital backup anywhere. However, large collections of photographs can also take up a massive amount of storage space within your home. If you want to clear some space, you should consider renting a storage unit or locker to place your photograph collection within. However, before you move your photo albums out of your house, you need to make sure your photographs are properly protected so that they will not become damaged while in storage.
You should never let your photos be stored in loose condition: this exposes them to too much risk of being damaged. Further, never let photos come into contact with each other, as the ink from each photo can cause chemical reactions that alter their appearance. Make use of specialized, acid-free storage containers, like photo albums or individual sleeves, to keep your photos safe and separated. Further, when moving photo albums or sleeves into a storage unit, avoid using cardboard, since it will not offer any sort of protection against moisture. Plastic boxes are a much better bet – but if you have to use cardboard, make sure you use a thick, corrugated one that can stand up to some abuse without falling apart.
Beyond making sure that your photographs are stored in the proper materials to reduce the chance of damage, you should also make sure that the containers are placed properly within a storage unit to minimize the amount of risk that they are exposed to. Never place boxes directly on the floor, since the temperature will seep into the bottom of your box and potentially cause discoloration to sensitive photo ink. Instead, make use of tables, pallets, or shelving units to store your photos off of the ground: this also reduces the risk of your photos suffering from water damage in the event of a leak or flood.
Finally, an important thing to take under consideration when choosing a storage unit is climate control. Climate-controlled storage units, like their name would suggest, offer a moderate temperature and humidity level within your storage unit or locker, which is maintained through a HVAC system. This reduces the risk of moisture buildup, temperature fluctuations, and a whole host of other environmental factors that can cause damage to your sensitive and fragile photos. While climate-controlled units do represent an added expense, it's important to weigh that expense against the value of your photographs, especially if you cannot replace damaged ones.