Tarotwolf
Just my three cents worth, try a spray sealer, varnish, ect. on an old deck from a thrift shop to practice your techniques. A fixative will work, but is designed specifically to stabilize the pigments apllied to a substrate. A sealer is designed to completely cover a substrate. You can use almost any art spray that says "archival" and you should be fine with yellowing problems. If you're really concerned with yellowing, spay a ph neutralizer on the cards first. It's carried at any framing supply house (designed for use on newsprint prior to framing or laminating). A good video to watch is linked below, the techniques are the same applied to paper. One tip is to spray several cards and then move them to the side several feet away using a piece of paper to pick them up from underneath. This will prevent them from possibly sticking to the protective newspaper covering your work surface.
https://m.youtube.com/watch?v=mZyPaOJRuYM
One thing you need to understand is that the sealed cards will not "feel" the same and may ruin why you love them in the weathered condition they're in now. Unless you plan on using them intensely, they aren't going to drastically degrade anytime soon.
One last tip, instead of applying a spray-on sealer why not try beeswax? Soften up a block of beeswax from an art supply store and lightly apply to both sides of the card with a soft cloth. I've used a burnishing stone as a follow up step but it's not absolutely needed. One of my favorites is a restorative wax made for furniture which comes in a bottle that has orange oil added to it. It' easier to apply, will darken the cards a bit and makes them smell like orange, but it leaves the cards with an "authentic" tactile feeling and protective finish. Straight beeswax will leave a clearer and slightly harder finish.
https://m.youtube.com/watch?v=mZyPaOJRuYM
One thing you need to understand is that the sealed cards will not "feel" the same and may ruin why you love them in the weathered condition they're in now. Unless you plan on using them intensely, they aren't going to drastically degrade anytime soon.
One last tip, instead of applying a spray-on sealer why not try beeswax? Soften up a block of beeswax from an art supply store and lightly apply to both sides of the card with a soft cloth. I've used a burnishing stone as a follow up step but it's not absolutely needed. One of my favorites is a restorative wax made for furniture which comes in a bottle that has orange oil added to it. It' easier to apply, will darken the cards a bit and makes them smell like orange, but it leaves the cards with an "authentic" tactile feeling and protective finish. Straight beeswax will leave a clearer and slightly harder finish.
