PE sheets

a while ago, i bought a whole bunch of PE sheets.  later, i found out that
it wasn't agricultural grade, but rather construction grade.  i noticed
that the agricultural grade was more or less perfectly smooth, while the
stuff i have seems to be bumpy.  before i waste a lot of time and effort,
should i not use this in my caps?  i have a feeling i have the wrong plastic.
Kevin Wahila