While I admit that some hobbyists may like the convenience of pre-scored sheets, I personally found it annoyingly limiting to be forced into these shapes. I can't, therefore, see more than a novelty use for this pack. It would make sense if Invent It! created a pack of each kind of sheet, because that would give consumers the opportunity to buy sheets for particular projects. This way, however, you have to spend a prohibitive amount of money to get enough sheets to make even a modest run of, say, magnetic business cards.

As for their general quality, Invent It! gives us slightly less powerful magnetics, and a material that is irrevocably stained by water. They are best on kitchen doors, or other areas of highly concentrated, magnetically conducive metal. For example, they hardly stick at all to stainless steel, and they also seem to have their functionality compromised by refrigerated or moist areas. Indeed moisture does seem to discolor the base color of the sheets, permanently changing that color from white to a very dull pearl. Fortunately, the material is such that the design itself will not bleed when wet, as is the case when inkjets print on paper.

I must point out that none of the three manufacturers I tested performed much better under what might be considered "extreme" conditions. None stuck to stainless to any great degree, and all discolored under moisture--though others did so less permanently. Invent It! did actually lose some magnetivity when exposed to water after adherence, actually curling slightly under the strain. Other manufacturers, notably Xerox, seemed to have slightly improved magnetics overall, sticking better to more types of metallic surfaces. None seemed eager to be used on already-moist surfaces, but Xerox in particular seemed to withstand moisture better if, for instance, condensation appeared after sticking the magnet to the surface.