Many companies combine trademark and design patent protection (as explained here). But we think a better choice for you and your logo would be to bypass the expense of design patents and just seek trademark protection. When your logo functions like a trademark, you can stop others from copying from a complete class of goods (for example, lawn furniture) rather than just the specific goods for which you obtained design patent protection. In short, trademark protection would save a great deal of money and achieve more expansive protection.
What's the Locarno Class? The Locarno Classification system is an international classification system for design patent protection. The U.S. uses a dual classification system that combines Locarno with the U.S. classification system. This improves access to U.S. Design patents in foreign search files.