fibre paper by another name?
Fiber paper traditionally was a minimum of 0.5mm thick. Now for many years we also have had “Thinfire”. Yes they both are fibre papers, but have very different characteristics.
Thinfire turns to powder so only if your practices are very careful can you use it again – and as many times as you don’t disturb it, because it is a separator, even having been fired several times.
Other, thicker fiber papers are made up of ceramic fibres and have longer lives with equavlent treatment. It does give a coarser texture to the back, but this can be reduced by smoothing on dry batt wash. If you do not disturb it, it will last for a long time.