The Propers are those texts which are interpolated at particular points in the Ordinary of the Mass.
Specifically, they are:- The INTROIT, the COLLECT, the EPISTLE, the GRADUAL, the ALLELUIA (or, on some occasions) the TRACT, the HOLY GOSPEL, the OFFERTORY verse, the SECRET, the COMMUNION verse, and the POST-COMMUNION prayer.
These collections of Propers are designed to be printed on A4 paper (landscape), folded and distributed to the faithful so that they can follow the texts as they are used and also, to encourage that they be taken home and used - for study or devotion, during the week.
The text of the INTROIT, GRADUAL, ALLELUIA (TRACT), OFFERTORY and COMMUNION in all the Propers which are made available here, has been modified to match the words used in The English Gradual, so that where the Propers are sung, the faithful may be able to follow the text (and, perhaps, sing along).
A word of caution. If you distribute these sheets at a low Mass, use one at the altar, don't confuse people by giving them one text and then reading something different from the missal.