Individually Quick Frozen (IQF) vs. Vac Pack? The fish come from the same source and the same plant. IQF is flash frozen where each fillet is frozen with a slight glaze and you can grab any number fillets you want at a time - just like the picture shows - they are not frozen in a block. Vac Pack are packaged in roughly one pound plastic and the air removed before they are quick frozen. Vac Pack will last longer in the freezer, but you need to thaw out the whole 1 pound. Choose whichever you prefer.