I worked in the nightmare of publishing for years at a bimonthly magazine, which tempers the following response. Unless you know the editor to be very reliable, your images are at great risk of loss, and even if you know the editor to be reliable, are at risk of abuse at the publisher. If they are important images to you, ones that you wish to use again, you should send dupes. Good dupes are more than good enough for most all publishing needs. If your images make it into the publication, they will have been handled by many people who are not obsessively concerned about archival conditions. They are generally in a hurry, and just want to get the image out of the sleeve, remove any obvious dust with whatever is handy, and get the image scanned.

A 35mm image scanned in its frame is never separated from its label. The medium format or large format image must make it from the scanners back to its correct sleeve, which can be quite a journey.

Where I worked, a publisher of several magazines, the images were first scanned at low resolution for placement in house, then sorted and numbered, then sent overseas. Scanning experts there scanned the images at high resolution for the printer, and the images were returned in a box, generally well organized. But it was up to me as the editor, being personally familiar with the images and the photographer, to get them sorted and returned. At this point, a minimum of two or three months had passed since the initial submission, and more likely a year. The transparencies definitely suffered from all the handling and cleaning fluid.

One editor who worked for years at the same publishing house always had a pristine desk. One day well after he had left for another job, someone was cleaning out the cavernous warehouse and found a huge file cabinet filled like a dumpster with years of floppy disks, slides, and transparencies.

Anyway, if the images are important I suggest sending dupes, and labelling them the best you can.