Wood is hygroscopic and expands and shrinks with changes in moisture
content. Maintaining humidity levels around 60-70% RH is critical in
temporary storage facilities for wood. If the relative humidity is not
maintained the wood loses his moisture to the air and will wrap and
crack.
Paper like wood is hygroscopic and relative humidity below 50% of the
surrounding air causes paper to shrink curl and lose dimensional stability. Humidity control will prevent moisture loss of the paper after drying.