When choosing between IP65 and IP68-rated LED strips, there are some considerations to take note of.
IP65 is generally selected when we need to account for splashes of water getting onto the strip, so it becomes ideal for a kitchen setting if installed near a sink/work counter. However, IP65 can only take so much abuse and it should be noted that while the top coating is well-protected, the underside - which has the 3M tape - offers a very limited amount of protection.
On the other hand, if you absolutely must have a strip installed outside, or within a swimming pool/pond, then IP68 affords better solutions. These strips perform far greater under extreme weather conditions and come ready-made for installation. Unlike the IP65 LED strips, Hi-Line's IP68 strips also feature full protection on the underside, where the 3M tape is.
Be very careful when shopping online for IP68 strips and research well, as some retailers list these types of strips without the fully appropriate protection listed above.
One other thing to take note of is that unless you absolutely require full protection, IP00 LED strips are the best to consider, even in the kitchen area, where you can still be careful around them. The reason for this is that IP00 has a much lower failure rate than IP65 and above, which is why you'll notice that warranty varies from strip to strip; this is simply fact based on the technology currently on offer and doesn't have anything to do with customization or overall quality.
Again, it's a case of making sure to install only what you really need. This way, you can avoid potential pitfalls and overcomplicating things later down the line.