Separating stuck together baseball cards requires patience and careful technique to avoid damaging the cards. The key is to go slow and use gentle pressure and solutions to break the bond between the cards without tearing or creasing them. There are a few different methods that can be tried depending on how tightly bound the cards are.

For cards that are just lightly stuck together, you can try carefully working your fingernail around the edges to gently pry them apart. Move slowly around the perimeter and apply gentle increasing pressure. Talk or hum to stay relaxed as you work. If any portions don’t want to separate, don’t force it. Move to another spot and come back later.

Once you’ve worked completely around the edges and loosened some of the bond, you can try carefully inserting a playing card or business card between the stuck areas as another prying tool. Slide it back and forth to slowly break the seal. Go millimeter by millimeter checking for separation. Patience is key here to avoid damaging delicate surfaces.

For cards more firmly fused, you’ll need to soak them to loosen the adhesive bond. Submerge the stuck area of the cards in lukewarm water for 5-10 minutes. The water helps dissolve any oils or residues causing them to cling. You can also try applying a few drops of rubbing alcohol which can help break molecular bonds. Let it soak in for a bit before trying to separate.

Gently test for readiness by inserting another thin card between and wiggling it side to side. Don’t force it. If they still feel stubbornly stuck, give it more soak time. Once you start to feel some subtle movement, you’re ready for the next step of careful separation.

Have paper towels handy to blot away excess moisture so the cards don’t get soggy or warped. Then slowly work your fingernail or thin card around the perimeter again. At this point the soaked adhesive should be loosened enough for a clean break with minimal pressure. Go section by section so you can concentrate effort where needed.

For really old or stubborn cards that have been glued together for decades, you may need to do repeated soak cycles. Keep sessions short like 5-10 minutes to avoid over-saturating the paper and warp the cards. Air drying in between soaks also helps prevent damage.

Another trick is to very carefully apply a tiny amount of silicone-based lubricant like petroleum jelly along the seam after soaking. Let it permeate for a few minutes before attempting separation. The lubricant helps prevent cards from re-sticking as you gently work them apart.

If all else fails, you can try soaking overnight as an absolute last resort. Make sure to weights the cards down so they lay absolutely flat without warping. But extending soak times increases damage risk so it’s only recommended if prior gentle methods have proven futile.

Most importantly, go slowly and be willing to take breaks if you start feeling stressed or frustrated. Rushing the process will only increase chances of tearing. Having soft classical music playing can help promote a relaxed atmosphere. With enough patience and the right techniques, stuck baseball cards can usually be salvaged without damage using methods above. Always approach with care and don’t force anything prematurely. Perseverance and a light touch will save more cards than aggressive prying ever could.