Like Ed I'm not too worried about the make as I just just the standard yellow; orange; red; grad ND and circular polarizer. Looking at modern ones I see no difference when side by side.

When I worked at a camera store though we occasionally had some old B&W and Nikon filters come in on the lenses we had offered us with people upgrading or going over the wall to digital. Now those old filters were beautifully deep and rich colours. Sadly none ever came in big enough to fit my lenses

Jim sweety wrappers are just as good for most things but less convenient than real ones, there again you can't eat the contents of a manufactored filter