and long leather fibres have the unique advantage over hammer milled fibres that blends with textile fibres can be carded without a substantial proportion being ejected during carding unlike carding airlaying plant is specifically designed to handle relatively short fibres and the leather fibres produced by the aforesaid textile means can be near the limit of fibre length for such equipment and fibre length and operating procedures need to be adjusted appropriately thicker webs generally need higher pressures to provide the deep initial penetration needed to entangle the interior available pressures in hydroentangling are commonly around 200 bar which is sufficient to entangle 490 gsm of web in the example higher pressures are available and have the advantage of allowing higher carrier belt speeds but need more expensive pumping equipment web weights of the order of 800 gsm can be processed which is sufficient for most leather applications and is beyond what is normally considered feasible for hydroentangled artificial leather even for more easily entangled synthetic fibres using conventional means alternatively where very thin products are wanted and a non leather appearance is acceptable on the back face the fibre layer on the back may be omitted altogether bringing web weight down to 290 gms or less fibres in the single remaining layer will key fully into the fabric from one side despite having no fibres on the opposite side to which they can link as with normal hydroentangling jet diameter jet spacing and pressure are all factors which determine the hydroentangling energy supplied to.