The best vacuum bagging frog material is this mesh from Hypervent, part number 3950. http://www.hyperventmarine.com/ .
It is intended to go under mattresses in boats, but is also unmatched under the intake of a vacuum pump.  Good under your laptop computer too, keeping the airflow going.

It is sharp enough to damage the bag, so I put a batt of bleeder cloth over it to protect the bag.

Below, the lot sucking.  With my favorite corner seal, Liquid Nails Projects. $1.75 a tube.  After a day it dries out and can be pulled off of the bag easily so the bag can be reused.