White Seahorses on Turquoise by silhouette_emporium
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I was wandering around Zazzle's forum and thanks to nyxxie noticed that we can tile images on throw pillows at Zazzle.com. Here's a fun seahorse pattern using that option.
If you're looking for a polka dot seahorse pattern on a nautical pillow, you can change the size of the seahorse and pattern by choosing the "customize it" option.