What kind of tape should I use to support my knee and back?

Knee & back taping. Physiotherapists and patients use many different types of tapes and bandages. Adhesive, non-stretch (rigid) sports tape is generally the most appropriate to restrict undesired knee mobility or improve spine posture. (for knee or spine strapping 38mm is usually the most appropriate size). This should always be used in combination with hypoallergenic tape as an underlay, such as fixomull.
Depends. Depending on the condition, there are different kinds of tape that will provide support. If you need support for function while doing exercise, physio tape can be useful in support various joints such as the knee and back. There are various patterns to apply the tape, so seek a sports medicine professional trained in apply physio tape.