The paper used for bags is known as Kraft paper which is a brown heavy duty sheet of paper. It has the advantage of being relatively inexpensive and provides better protection from rain than the mesh bags. The Paper also has an advantage of providing more shade for the bunches than the mesh and reduces the number of dates that are get sunburn.
The disadvantages are that they are disposable and have the possibility of ripping during high winds. Another disadvantage is that they create an environment inside the bag so years when there is a lot of humidity, but no rain the environment that is created inside the bag can cause problems that is normally seen from rain. the final disadvantage is that the paper bag does not fully enclose the bunch and leaves the bunch susceptible to insects that the mesh would keep out
All in all the paper bag is a great choice for the Barhi trees due to the fact that most a Barhi are picked in the yellow stage and they create less of a mess should some of the dates ripen before the bunches are picked. Other trees that we use the paper bags on are the Zahadi and Khadrawi.
The mesh bag is made of a nylon material and the holes in the mesh a small enough to keep insects out, but it also allows air to circulate around the bunch which solves one of the problems associated with the paper bag. another advantage is that it covers the whole bunch and should some of the crop fall due to wind the mesh bag will catch the dates save that portion of the crop from being wasted. although they are more expensive than the paper bag they can be reused for many years and that will justify the additional cost.
The disadvantages to the mesh bags is they offer less protection from dust and no protection to the rain. In recent years we have experienced heavy monsoon rains and it has caused a lot of the dates in the mesh bags to sour and go bad while the dates in the paper bags fared much better.
The use of the mesh bag has become common place with the two most common dates the Medjul (Medjool) and the Deglet Noor and this is a trend that will continue. However the mesh does not work well on the really soft varieties because they tend to smash in the netting and creates a big mesh.
So in conclusion, if you were to ask me which type of bag you should buy I would have to say it depends on the situation because the effectiveness of either bag is determined by the situation.