All papers can be made acid-free with these Deacidification Sprays and Solutions. These products work to neutralize potentially harmful acids and provide a lasting protective buffer against future acid problems. The most common application of these products is on newspaper clippings, letters, awards, certificates, drawings, stamps and other paper memorabilia. Occasionally nozzles can clog. If you experience this problem, try cleaning the nozzle with vinegar. Be sure to follow package instructions when using these products.