Unlike a classic Bordeaux wine, videotapes are not known for getting better with age. They are susceptible to both physical damage and chemical changes that can make your family movies unwatchable. We'll cover some of the common issues that occur with all formats of analog videotape.
Physical damage
Videotape is a thin medium and many of the playback performance issues, such as dropouts or loss of audio, are due to physical problems with the tape housing or the tape itself.
Scratches – causes dropouts as well as stationary noise band lines for longitudinal scratches. Diagonal scratches cause noise bands drifting either down to up or up to down.
Broken tape – makes the tape unplayable though a splice can be made to repair this with possible loss of some footage.
Tears and stretching – causes the video image to skew to the left or right. Can be spliced out of the tape spool as a repair but the bad section of tape will result in lost footage.
Wrinkles – results in horizontal bands of picture noise lines rolling from top to bottom or bottom to top and crumpled tape can jam the playback VCR. The wrinkled tape can be spliced or professional tape restoration firms can mildly heat the tape to smooth out the crease.
Folding – an accordion-type folding of the tape usually caused when there is a lack of tension in the tape pack that allows gaps to form in the pack. Remedies are the same as for tape wrinkles.
Cupping – happens when the tape deforms in a U-shape that results in poor head-to-tape contact creating dropouts or noise lines that cannot be removed with player adjustments. Flattening techniques such as those used for wrinkles may be required.
Edge damage – when the top or bottom edges of the tape are affected which can lead to significant playback problems. Depending on the type of damage, some of the remedies discussed above may be needed.
Chemical damage
Besides the physical problems that occur with videotapes, the chemical composition of magnetic tapes poses aging issues as well. VHS tape, as an example, is composed of a polyester plastic base coated with a polyester urethane binder material containing magnetic oxide particles. The oxide particles are what hold the video signal. Changes in the magnetic oxide are usually not significant over the lifetime of the tape. The main chemical degradation problem is the decomposition of the binder layer via hydrolysis which is also known as “sticky-shed syndrome". This causes stickiness when the tape is unwound, squealing with the tape is played, and the binder and oxide particles flake off the tape resulting in missing binder material.
In addition to "sticky-shed syndrome", other chemical breakdowns can also reduce the life and playback quality of videotapes:
Loss of Magnetic Charge
All types of analog tapes use magnetic charge to store the video and audio data on the tape. Magnetic charges weaken over time which results in loss of detail and dull colors. If you bought high quality tapes, this degradation may not be as severe as with many bargain brand, lower quality tapes.
Demagnetization
Videotapes use magnetization to store the video information so they are vulnerable when placed close to a magnet. Tapes stored close to stereo equipment or other electronic devices with magnets can have some or all the home movie recordings damaged.
Moisture
For those living in humid areas, moisture is no friend of analog videotapes. In even moderately humid environments, the binder part of the videotape can absorb moisture making it sticky. This can damage the tape or even destroy it completely, as well as potentially damaging VCR heads.
Mold and Fungus
Often caused by storing tapes in humid environments, mold and fungus are serious problems for videotapes and for anyone breathing in the mold spores. The mold is feeding on the tape and when it's active, it will smear when rubbed. If inactive, it looks like powdered sugar on the top of the tape roll. Mold is very invasive and will penetrate between layers of wound tape. Although mold can be removed from videotape by surface wiping or vacuuming the exterior of the wound tape, only experts in mold remediation should attempt to remove this from an unwound videotape. Mask wearing is a must. Moldy tapes should never by played as they will contaminate the playback machine and extensive cleaning to the VCR will be required.
Videotapes were never designed to be a long-term medium. Unlike 35mm film used by Hollywood, the physical and chemical design of analog tapes do not retain images in the same manner. Just compare the quality of an "I Love Lucy" episode, which were all shot in film, to a game show or talk show recorded on videotape from the same time period. One looks great while the other is almost unwatchable. Digitizing videotapes puts your recorded memories in a non-degradable file format that can be easily moved to newer digital formats in the future.