formatting usb mac vs pc

[BabsMo]

I bought a usb 16g from photo co. I was using my mac. I had to remove a folder to create more room. But, the used space was somehow still on there. So we reformatted on mac, but client couldn't view. I put usb back in mac and reformatted FAT 32. brought to my pc, could not open it. It only wanted to format usb. Sooo, I transferred all of those photos back on mac and now want to reformat so that others can use on their computers. I don't know which one to plug in Fat (default)? AND, do I put in 8192 bytes or 4096...confused to say the least

 

[CountMike]

Fat32 should be detectable and readable on all OSs but has 4GB single file limit. You can also try exFat, doesn't have that limit but for Mac you may need a plug-in to read and write to it.
http://www.laptopmag.com/articles/format-drive-for-windows-and-mac