Mylar vs. PVC: The Storage Material That’s Ruining Vintage Currency

The plastic holders protecting your currency might be destroying it. PVC—polyvinyl chloride—once dominated currency storage products. Those flexible vinyl flips and soft plastic pages release acids that attack paper and ink, causing irreversible damage to notes stored within them. Understanding the difference between safe and dangerous storage materials protects your collection.

The PVC Problem

Polyvinyl chloride requires plasticizers to remain flexible. These additives—often containing chlorine compounds—migrate out of the plastic over time. As they leach onto stored currency, they leave oily residue, create haze on paper, and accelerate chemical degradation of inks and fibers.

The damage appears gradually. A note stored in PVC might look fine for months or even years. Then haze develops on the surface. Colors begin shifting. The paper takes on an unhealthy sheen. By the time damage becomes visible, significant degradation has already occurred throughout the paper structure.

Older collections frequently contain PVC damage. Currency holders from the 1970s and 1980s often used PVC because it was cheap and flexible. Collectors who inherited or purchased older collections should examine their holders carefully and remove notes from any suspect materials immediately.

Identifying PVC Materials

The sniff test helps identify PVC. Plasticized PVC has a distinctive chemical smell—the “new shower curtain” odor. Inert materials like Mylar have no odor. If your currency holders smell like plastic, they likely contain PVC.

Flexibility provides another indicator. Safe Mylar holders are somewhat stiff and crinkle when bent. PVC holders are soft and flexible, bending easily without creasing. Very soft, pliable holders almost certainly contain harmful plasticizers.

Visual examination of stored notes reveals active damage. Haze, discoloration, or oily residue indicates PVC problems. Remove affected notes immediately and store them in safe materials. The damage won’t reverse, but stopping exposure prevents further deterioration.

Mylar: The Safe Alternative

Mylar (polyester film) provides chemically inert storage. Mylar doesn’t release plasticizers, acids, or other harmful compounds. Notes stored in quality Mylar holders contact only stable plastic that won’t contribute to degradation. Professional archives and museums use Mylar exclusively for paper storage.

Quality Mylar products cost more than PVC alternatives. The price difference reflects material cost and proper manufacturing. For currency worth protecting, the premium is trivial compared to the value at risk. Saving a few dollars on holders makes no sense when notes cost hundreds or thousands.

Mylar thickness affects both protection and usability. Thicker Mylar (3-4 mil) provides better physical protection and lies flatter. Thinner Mylar (1.5-2 mil) costs less and takes less storage space but offers less rigid support. Most collectors find 2-2.5 mil Mylar balances these factors well.

Other Storage Options

Currency albums vary in safety. Premium albums use Mylar pages with acid-free interleaving. Budget albums may use unsafe plastics or acidic paper. Examine any album carefully before trusting your currency to it. The price usually indicates material quality—very cheap albums likely cut corners on materials.

Acid-free paper envelopes provide adequate short-term storage. Notes in paper contact only paper—no plastic concerns. However, paper offers less physical protection than rigid holders. Paper storage works for temporary housing or budget collections but shouldn’t house valuable material long-term.

Third-party grading holders from PMG and PCGS use inert materials designed for indefinite storage. Once graded and encapsulated, notes reside in tamper-evident cases engineered for preservation. The grading fee includes permanent archival-quality housing.

Transitioning Your Collection

Examine your current storage immediately. Smell the holders. Check flexibility. Look for damage on stored notes. Any concerning signs warrant action—waiting allows continued damage to valuable material.

Replace suspect holders systematically. Purchase quality Mylar holders sized for your notes. Currency holders come in sizes matching large-size and small-size U.S. currency, fractional currency, and various world note dimensions. Get the right sizes before starting replacement.

Handle notes carefully during transfer. This is an opportunity for damage from careless handling. Use cotton gloves. Work on clean surfaces. Transfer notes from old holders to new ones without excessive manipulation. Take your time rather than rushing through a large collection.

Ongoing Vigilance

Even proper storage requires periodic inspection. Check stored notes annually for any signs of problems. Verify that holders remain in good condition. Catch any issues early before they become severe.

Storage conditions matter alongside holder materials. Mylar won’t cause chemical damage, but improper temperature, humidity, or light exposure can still harm notes. Quality holders are necessary but not sufficient—they must combine with appropriate environmental conditions.

New products enter the market constantly. Some claim safety without meeting standards. Stick with established suppliers known for archival-quality materials. Collector forums and grading company recommendations help identify reliable sources. Don’t experiment with your valuable currency.

The Bottom Line

PVC destroys paper money slowly but relentlessly. Every day notes spend in harmful holders causes additional damage. The solution is straightforward: identify problem holders, remove notes immediately, and replace with Mylar alternatives.

The cost of proper holders is trivial. A lifetime supply of quality Mylar holders for most collections costs under $100. Compare this to the value at risk—even modest collections contain notes worth more than storage materials. The decision should be automatic: invest in proper storage today.

Your collection represents financial investment, historical connection, and personal passion. Protecting it from preventable damage simply makes sense. Don’t let a few dollars in holder costs cause thousands in collection damage.