If Biden Had Been Supported By...
Society & Culture3 mins ago
No best answer has yet been selected by SaxyJag. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.pva glue dries like a clear plastic, this is a water based glue but is hard to remove when dried and does not soften easily once dried.
paper sticking gums come either clear or some times golden in colour, these are water based and may soften with a application of water to moisten.
if the glue used is a tea/coffee brown coloured type of glue or even clear, but of a hard rubbery stubstance don't do anything. these glues need strong solvent chemicals such as turps to be removed. this will damage the photo even more. seek expert advice rather than tackle the unkown
if the glue is in spots, at the corners of the photo, you could try,( if you feel confident enough to do so ), dampening the the paper on the back carefuul with a sponge to re-soften the glue. only try this though, on very sturdy photos and ones in nearly new condition.
don't try this on postcards as the inks will smudge easily.
i agree with alan to get expert advice though.