Top critical review
21 people found this helpful
Only buy yellow invisible pen
on February 29, 2012
I bought these pens for an invisible ink activity at my daughter's 7th birthday party. The blue and red pens leave a wet mark when writing your message and are visible. These colors take a long time to dry and messages messages can be read even when dry (in a light white color, not blue or red), which was disappointing for "invisible" ink. In addition, the red and blue colors don't glow well under the UV light.
The yellow worked great and was what I expected: dried almost immediately and couldn't be read when held up to a regular light. It glowed under the UV light. I would recommend buying ONLY the yellow pens singly.
In addition, the fine tips of the pens are not very sturdy and one pen tip was broken by my 3 year old pressing too hard on it, so these pens are probably best for experienced writers, ages 6 and up.