I just received the InvisiClue book for the Infocom Trinity interactive fiction game. I thought any highlighter pen would allow the clues to be viewable, but it did not work. I think I need a special kind of pen/marker to see the clues. Does anyone know which markers/pens work with the InvisiClues books?
Try some vinegar in a cotton bud. In that era, a lot of systems used vinegar as the reactant for "invisible ink" pens.
Chesh
I tried the vinegar suggestion and it did not make the clues visible. Along the lines of your suggestion I tried a UV light that I had on my desk. When you shine the UV light on the blank text area you can see the clue text. It's a little faint, but readable. Unfortunately, I was not able to see the clues that had been "highlighted" by the prior owner of the book with the UV light. I did find a text file on the web that had all the clues typed out. I can council this text file when I get stuck and the UV light does not work. Thanks for the help.
Invisiclues was interchangeable with the orange invisible-ink pens used by Lee Publications in their Yes & Know and Guess & Show activity books.
It should also work with the green pen for their combination Invisible Ink & Magic Pen Painting books.
It won't work with the purple pen for their Magic Pen Painting books. The purple pen was just a wetting agent, not invisible ink developer.
Unfortunately Lee Publications is out of business, so new books & pens are becoming scarce. I see bad reviews for them on Amazon (secondhand, missing pen, etc.) but some eBay sellers claim to have shrinkwrapped originals.