Stix 2 glue pen 2 in 1, rolling ball, acid free so photo safe, fine metal nib, no squeezing as new pump action.  

When wet use as an ordinary permanent glue.  Leave to dry after applying and it then becomes a removable adhesive.  The glue goes on blue and dries clear so you can see where it's being applied.

To increase the flow of the glue replace the cap several times to pump the nib, reduce the glue flow by holding the pen upwards and pressing onto a firm surface to release the pressure.

Clean the nib and replace the cap after every use.