Stencil is a thin sheet of card, plastic, or metal with a pattern or letters cut out of it, used to produce the cut design on the surface below by the application of ink or paint through the holes.
BGA rework stencils are manufactured from a polymide film with a high-temperature adhesive covered with a release liner .It is same type of material you have been using with bar code labels and for protecting gold fingers during a wave soldering process.
BGA Stencil is a stencil for soldering China-phone universal Cell Phone, (49 in 1).
SC6825C, MT6582, MT6575A, MT6572A, MT6285, MT6252CA and 39 in 1
1x BGA Stencil MTK A425