I've been using a bag for mashing since my first grain brew 15 yrs ago - never read about it, its just the obvious thing to do. I buy a length of muslin cloth and sew it into a rectangle. You fold one side so you only need to sew 2 sides, the short side for the bottom and the long side for the side. You don't need any skills, just in-out-in-out with an upholstery needle, takes about 10 minutes. The hardest part is going into a spotlight (fabric) store to buy the cloth, gives me shivers just thinking about it. These days I mash in an esky and don't sew at all, just lay the muslin in the esky and pour the grain and hot water in on top, then use gravity to siphon the wort out.
They also work really well for fermenting red wine on the skins, at the end you just pull the bag of fermented skins and seeds out and put it in the press, makes it really simple, most home winemakers do it this way
They also work really well for fermenting red wine on the skins, at the end you just pull the bag of fermented skins and seeds out and put it in the press, makes it really simple, most home winemakers do it this way