When it comes to the care and cleaning of their window treatments there can be some anxiety associated with the process - especially if you don't know much about their fabrics or construction. Briefly we'll touch on a few of the things a knowledgeable professional blind or drapery cleaner should discuss when a cleaning project is pending.
Age: The age of a window treatment provides a context under which several factors should be considered. How long any material has been subject to the effects of ultraviolet light and other potentially harmful environmental factors is going to determine its condition. Just as plastic degrade, discolor, loose elasticity and become brittle over time, the same is true of other synthetic or natural fibers. While sun damage (or even sun rot) may be minimized by UV tints or drapery liners the accumulative affects of long term exposure are not totally removed. Left unprotected in direct sunlight fabric colors will fade (discolorations are more distinct in some fabrics than in others) an the strength of fibers will degrade. Stresses associated with some cleaning processes obviously pose a threat to the integrity of weakened fabrics. Don't forget that the thread or adhesives used to secure the hems or other components of the window treatment also are frequently compromised and may easily fail. When the treatment is just hanging in the window one sometimes tends to overlook some of the warning signs of aging. Upon a closer inspection however, you may see evidence of fading color on the back edges or other warning signs. Test the hems, inspect the fabric and any linings to determine if there are reasons for concern with the cleaning method being considered.
Shrinkage: Shrinkage is a common concern, but one that is also often misunderstood. In simple terms, shrinkage occurs when woven fabrics either expand or slide in the weave of the fabric and change the tension of the weave. Many natural fibers, like cotton, swell as they absorb water and so it is best to pre-shrink a fabric before using it. For a number of reasons however in the drapery and window treatment industry custom made treatments are often not pre-washed or pre-shrunk before construction. This is why the local dry cleaner has the client sign off on liability for shrinkage before cleaning draperies etc. What some consumers overlook however is the potenial for "environmental shrinkage". Significant fluctuations in the humidity can affect some fabrics as well. Have you even seen a drapery that hangs a bit shorter over a floor heat vent ? Changes in tension due to the weight of the treatment or environmental factors can also can lead to stretching of the fabric as well. For new fabric to change its length by several inches or up to 3% is actually within what the fabric mills consider normal in some cases. If one has fabric blinds or sheer products the issue with shrinkage is not so much of a concern as distortion due to extremes in heat or tension that can affect the hang of the fabric. Puckers or sagging may develop naturally over time with some types of fabrics, cleaning will not remove this. Dry cleaning methods (solvent based instead of water based cleaners) are appropriate when shrinkage is a concern for many finer drapery fabrics. For many fabric shades or verticals wet cleaning may be safe as long as other factors (such as glues or room darkening laminates) don't preclude it.
Color Loss: Colors are applied to fabrics and shades in different ways. If the fabric color was derived from a dying process and it was never washed it is possible there are still loose dyes (over dye) on the fabric that will be removed when it is first cleaned. The loss of this dye typically doesn't affect the intensity of the colors, however improper methods are use to clean a fabric loose dyes can travel and bleed their colors into other areas of a multicolored design. Care must be taken when cleaning some types of prints or in working with fabrics that are prone to bleeding colors. Dry cleaning and quick drying are two common ways cleaners use to manage these issues. Use of incompatible cleaning chemicals on a fabric can lead to color loss and discoloration. For this reason no spot cleaning should be done without first testing for color fastness in an inconspicous spot on the treatment such as the back of a hem. Of course color shifts or loss due to the affects of sun fading or oxidation can not be reversed by cleaning. Occassionally shifts in color are the result of other environmental factors (darkening from candle soot etc. ) which may or may not be successfully managed with cleaning depending upon their cause, the fabric and their composition as well as the professional expertise of the cleaner.
Dark colored fabric shades or blinds can be safely cleaned by appropriate methods. Their colors may be affected by stronger cleaners, spotting agents or degreasers so addressing spots in some fabrics is not as easily managed as in others.