I bought these pens when they first came out because I LOVE glimmer pens! I have the Wink of Stella pens, which were the first on the market, then I bought the Spectrum Noir Clear Sparkle brush markers, before purchasing the Tonic Aqua Shimmer pens.
I did a side by side test using each of the markers on a matching solid stamped image. The results were as follows: Wink of Stella had the least sparkle showing, Spectrum Noir had considerabley more sparkle. The winner, without a doubt, was the Tonic Nuvo Aqua Shimmer marker. The sample of it showed that it was evenly covered with tiny sparkly bits, that caught the light much more effectively than either of the other 2 pens.
Note: You MUST be sure to gently shake/roll the barrels of the pen before you start to stroke on the color. That is the only way you will get the sparkles to mix with the carrying agent before it is used. (This holds true for all of the pens with glitter in them!). It is also a good idea to store the pens (any of these mentioned), with the pen tips UP. The Wink of Stella package recommended this, and it worked well - it also works well for the other 2 brands.
I definitely recommend these Nuvo Aqua Shimmer pens. They are less expensive than the other brands and produce a more impressive shimmery result!
The pen is a great design and great to use, However I am disappointed in the appearance when used. The packaging has an example on the back from some type of product with glitter. It is NOT an example of what the pen actually dispenses. The example on pack looks like stickles. These pens , when used are exactly like Zig, Wink of Stella , GL Clear. I did a side by side comparison. But the pack of 2 was reasonable in price, I wish they were like what they show on the back of package.