A racket covering is the part of a racket that covers one or both sides of the wood part of a racket.
The wood part is usually referred to as the "blade" . But lesser known names are "frame", "baseboard" etc
A blade is multiple layers of wood and can also contain layers of composite material such as carbon, kevlar, arylate, graphite etc
(The top layer of a blade has to be wood & total content of a blade cannot be more than 15% composite material)
There are 6 types of racket coverings
1. Spinverted (also known as spinny inverted or pips in (or just "in" in Official ITTF documents) or reverse or backside)
2. Short pips out (also known as just "out" in Official ITTF documents) )
3. Medium pips out
4. Long Pips Out (also known as just "long" in Official ITTF documents) )
5. Anti Spin (also known as just "anti" in Official ITTF documents) )
6. Sandpaper
There is also a racket covering with special name Hardbat, which is a subset of Short pips out
All rackets covering above (including hardbat) are approved for use in ITTF competitions except Item 6 (Sandpaper)
All 6 rackets covering above (including hardbat & sandpaper) are approved for use in
WdTTF
competitionsIf you are a recreational or casual player it doe snot matter what you use
However new players who wan to be competitive players especially younger players should NEVER play with hardbat or sandpaper, because the strokes & techniques are very different from regular tabletennis (known as sponge domain tabletennis) & this would confuse players and can severely stunt player development in mainstream tabletennis. Though hardbat (and sandpaper also in