[FrankWakefield]

Nylons... what Rhett said. DRY cards only, gentle and patient.

Buy a T58 fish card and soak it. I'm talking immersed in water for a day or two. You'll see dirt accumulate in the bottom of the glass or cup. The card stock in a T58 is the same as a T206. Some gunk can be gently nudged loose from the surface. Don't get aggressive and dig craters in the card. Buy a few dirty, gritty, worn, gunky T58's on eBay. search 'tobacco fish card', maybe add Sweet Caporal to the search. I think most folks who are selling T58's are unaware of the Burdick designation. T=twentieth century, 58=58th series of tobacco card cataloged. (N was for nineteenth century) Practice soaking...

Goudey cards and other 30's cards (eg; National Chicle Sky Birds) area a sandwich of different papers. There's a nice piece of paper atop the front, inside is paper with a thicker coarser pulp. You can soak them, but not for a long time at all. Practice on a beater card or two.

Blot those cards. If you soak it you gotta get the water back out. Blot and press them. A few paper towels, nice white typing paper, then stack some books on top. Blot for half an hour or so then change blotting paper.

Someone on this board knows or remembers more chemistry than I do... water is a universal polar solvent. the outer hydrogen atoms line up oddly, they are polarized to 107 degrees I think. Not 180 degrees... Alcohol oil mineral spirits, that stuff is non polar, the outer at0ms space out symmetrically. Simply put, oil and water don't mix well... If tempera paint is on a window, wash that off with water, not paint thinner. If oil paint spills on the floor, don't get some paper towels doused with water, you need mineral spirits.

If there's a water based ink on a card, then soaking it is gonna weaken the ink and it'll bleed across the card. If it's a permanent or oil based ink, a LITTLE soaking shouldn't make the ink spread.

Consider adhesive tape on the back of a card.... water soaking may ease that tape off, but you're fooling yourself because what really may have happened is the paper loosened and separated, and your now freed piece of tape will have tiny bits of card surface still attached. So what to do... get out 91% isopropyl alcohol. Try that on a bit of gunk.

NOTE WELL: the printing ink when the card was made was almost certainly a non polar ink. That means that your non polar solvent will dissolve it, remove it, discolor it. A Qtip is a useful tool...

I've used lighter fluid to return dried cellophane tape gum to a softer more pliable state when removing it from the back of Goudy cards. Again, slow and gentle. Then, after doing that, I washed it up a bit with rubbing alcohol (think several hours and time passing on this, it isn't a two minute process) on Qtips. I mainly did this to work on the adhesive color left on the card back, but also to help dissipate and diminish the long lasting scent of the lighter fluid.

I don't mind a bunch of haters blasting soaking... consider that I don't send cards off to get graded. But I have broken out several dozen cards outa plastic slabs. I've saved a bunch of slips. It's my card. If I gently erase a pencil mark that wasn't on the card originally, then my card looks better and more like it did when first released to the public. I'm not grading and scamming anyone, I'm not painting or adding color or trimming... Realistically, most of the nice T206s that are in slabs were flour pasted into scrapbooks 100+ years ago and were soaked off in the 50s and 60s. Yes, soaked in bunches. The scrapbook pages would go in a tub, add water. Let soak overnight. Next morning the cards have floated to the top. Rinse them a time or two with clean water, blot and press... Golly, the great corners on most of today's cards survived because of the protection the scrapbook afforded. Cards left in the hands of grubby snot nosed kids (like I was at 8, 9, 10...) those cards look like most of the candy cards, with round corners, think E90-1s and ZeeNuts).

Taking nylons to a wet Goudy card gives me a mental image of me working on a scratch on my car with steel wool and a can of spray paint.