There are a lot of myths about videotape. Here are some of them, along with the facts.

- Myth No. 1: High-grade videotape gives you a better picture than regular videotape.Fact: Not necessarily. Sometimes so-called high-grade tape works better, and sometimes it doesn't. Manufacturers can call anything they want "high grade," so you have no guarantee that your extra dough is buying any extra quality. My own tests and those of Consumers Union have found no advantage to expensive tapes for most consumers.

- Myth No. 2: Use a new, unused tape when you are making a priceless recording.

Fact: A tape that you have never used before is the worst bet for an important recording. There are two reasons: First, you don't know if the tape has any flaws that could ruin your taping; second, tapes actually improve with each play for the first dozen times. The spinning video head drum polishes the tape and smoothes out any imperfections.

- Myth No. 3: Tapes make your VCR's heads dirty, and so you have to clean the VCR's heads every now and then.

Fact: Dirt makes the heads dirty. Good tapes are clean, not dirty, and you can play good tapes for months or even years without mucking up your VCR.

Dirt can get into your VCR in many ways - through dust and smoke in your house, through dirty rental tapes, and so on - but the use of reputable blank tapes won't make the VCR dirty. After a long time, tiny bits of tape residue may find their way onto parts of the VCR, but they seldom cause any problem.