Hypothesis: Using eyeshadow primer causes shadow to be more vibrant and stay on longer.
Procedure: On the first day of the experiment, I applied the Lorac eyeshadow primer to my whole eyelid before applying my Dior eyeshadow. I took a photo right after I applied my makeup, then another photo 12 hours later. I did not retouch my eye makeup at all during the day or before the second photo was taken.
The second day of the experiment, I repeated the same steps as above, but did not apply primer before applying my eyeshadow.
The top two photos were taken on the first day of the experiment, when I used the eyeshadow primer. The bottom two photos were taken on the second day of the experiment when I did not use the primer.
Twelve hours after my eyeshdow was applied with primer, some of the eyshadow had worn off, but it was still vibrant overall. Without primer, my eyeshdow was much more dull 12 hours after it was applied.
During the experiment, I also noticed that when I did not use primer I actually had to apply more shadow to get the same color payoff. When using primer, I only had to go over a single spot one time. When I did not use primer, I had to go over the same spot two or three times (when applying the light colors) to get the same color payoff.
Conclusion: My hypothesis is true! Using eyeshadow primer really does cause shadow to go on more vibrant and stay on longer. As an added benefit, it also allows you to use less eyeshadow.
However, I cannot say that this is true for every eyeshadow primer. I've only tried the Lorac primer, so I cannot speak for my own experiences with other products. I have heard that Too Faced "Shadow Insurance" primer is also very good though.
One more thing: People say that one of the most important reasons for eyeshadow primer is to prevent creasing. I guess I'm lucky, but my eyeshadow never creases (even without eyeshadow primer) so I could not evaluate that.
So tell me, do you use eyeshadow primer? If so, which is your favorite?