The two "gut" keys for me are (1) Size: Tigers big, Blacks small. The largest Blacks will be only as large as the smallest Tigers. (2) Yellow spots. Blacks have double rows of yellow spots on the forewing, double rows of yellow spots on the body, yellow spots on the hindwing ... Exhibit A: Papilio polyxenes f If you're lucky to see the light through the wings, a third key is that female Tigers are really dark brown, not black. What's hard for me is sexing Black Swallowtails when they are ambiguous. I believe this one is male because of the solid row of yellow spots inside the blue, but he might be best called "metrosexual."

Drive up to New York. You will make a lot of money. Farmer's markets are always packed. People line up to buy and pay. You can sell at very good prices. dcarch

I made it to the end in less that 30 minutes! Mostly just by randomly clicking all over the picture. Has anyone else made it to the end? Kittywhiskers

Lee John Philips, artist. An explanation of his current project, which you can follow on Instagram or Twitter (links on his site): I am currently cataloguing the entire contents of my late grandfather's tool shed. I estimate the project to take around 5 years and will involve me illustrating in excess of 100,000 items. http://www.leejohnphillips.com/