Material suitable for an advanced student will be beyond the beginner's comprehension. Material suitable for a beginner will lack challenge for an advanced student. It is essential that material matches the abilities of the student. Students usually react more favorably to bright, colorful, interesting, well-illustrated material. In other words, they should have a degree of authenticity.
Some materials are easier than others to photocopy.
We should question the extent to which everything is seen from the point of view of the writer's culture. However, it is important that, in an attempt to avoid the accusation of ethnocentricity, the material does not become paternalistic and condescending. When such a wealth of commercially prepared material is there for the taking, some teachers question the need to spend time generating their own material. In other words, learners are more committed to materials they have helped to create. In practice, most teachers probably use a combination of commercially produced and original materials.