One such visual trick that's been hidden with wavy lines may look like a simple pattern, but there’s more to it than meets the eye. The big question is: Can you read the hidden message?

Greggs fans have been left stunned after realising each pastry has a different pattern on its top, which is designed to tell ...

We know because sometimes, the pattern becomes ... the line are wavy. There are several skin conditions that can cause lesions and pigmentation that follow Blaschko lines along the body.