[matt_ny]

Not sure what you mean here - With Watson Visual Recognition, you can train a set of custom classifiers from your example images.

Then in a single API call, you can upload a batch or single image and get a score for each image for each class in all your classifiers. There are limits to the size of the ZIP files you can upload, that's true.

[matt_ny]

Maybe you were referring to the _demo_ of custom training, here: https://visual-recognition-demo.mybluemix.net/train ? The demo only classifies using one classifier at a time, but the API can do multiple at once.