The gland packing should be cut with a sharp knife to avoid fraying of the edges. Do not use scissors or hack saw blade etc. A heavy duty engineer’s knife or a sharpened ordinary knife would do.
There are two methods of cutting the gland packing, the first one is straight or at 90 degrees i.e. Butt joint and the second one is at 45 degrees i.e. skive joint. The taper method gives better sealing but is more difficult and skill oriented and the angle on both the ends should match properly or otherwise it would lead to more leakages. In places where there is an accessibility problem it is best to cut the gland packing straight.