When I ordered in March it said they can't promise the usual 6 weeks delivery right on the front page of the website. It still says that on the website now.
"We are currently experiencing a production delay. The normal delivery time of 6 weeks can not be promised. Orders are processed on a first come first serve basis too fulfill our committement. Thanks for the understanding. " - from sheetfilm.be website

By my calculation it's been about 11 weeks for my order personally but I have no clue what their production problems are and I have every faith that I'll get it eventually.