I recently found a place that's selling Ilfochrome for a dime, though it's slightly outdated (Dec 2005). I know that Ilfochrome is known for it's super archival quality...how does it hold up pre-exposure? Ilford's website says "FX 3X is practically a neutral conventional black-and-white fixer." Does this mean I can throw it into a b&w fixer if I want to test it for base fog? I've got TF-4 hanging around (though I believe it's alkaline). I could use something else if needed. Thanks.