page at my site may be of interest to your daughter and you...maybe even way more than you want
And you're right that a lot of the info out there about transferring is confusing to even wrong, or works only in certain situations a person has lucked into, etc.
My site is primarily about polymer clay, but for the transfer techniques many of the materials, equipment and supplies will be the same as transfers done onto baked/hardened
clay (or onto many other surfaces).
The info on that page has been collected over many years (though not attended to for the past few years**), so even though it's "organized" some techniques are seldom used now and substituted with better ways, and/or the info can be overlapping, etc...this is probably the biggest bear of a page I dealt with at my whole site for organizing/getting straight, correcting as new info came out, and it never got completely fixed, etc.
Two things in particular to notice and differentiate about categorizing "transfer" techniques:
1. Supplies, equipment, and execution matter:
...the type of ink matters (some techniques require "toner" which a heat-setting --plastic?-- powder used in photocopiers and laser printers; most regular printers use "ink" instead which is usually water-based and not permanent though some newer machines do use permanent inks and those will work better...for stamping inks, the pigment ones are good, but Staz-On and some other brands may work best?)
...the type of machine used matters (but that has mostly to do with toner versus ink)
...the type of paper (or other material) matters (some will hold and/or release toners and inks much more easily than others, for example)
...the technique, and how well it's done, matters though its execution is not always be the same across methods
2. There are "direct" transfers and "decal" transfers.
...decal methods result in an image embedded in or permanently on some kind of (often clear) film, that's then put onto the surface desired
......the packing tape method creates a decal, but a rather thick and not very flexible one
......there are many other ways to create decals though, some using special papers like t-shirt transfer papers, some using liquid polymer clay or other liquid mediums, and more
...direct methods result in all the toner/ink being transferred onto a surface by the end
......there are many ways to do direct transfers; some involve pressing or heat or "solvents"...some will work well on raw polymer clay, etc.
On that Transfers
page, the packing tape technique is a sub-sub-category under the sub-category called Non-Liquid Clay Mediums
. It specifies the use of toner
Also, if you stick to the decal methods you'll probably want to read the sub-sub-sub category in that same category called Getting the Paper Off
under "Basic Instructions, Direct & Decal" as well.
(I don't know much about stamping onto metal for the most durability when it will be abraded, subjected to solvents, etc.)
** If you also want some of the info I've collected to add to that Transfers page but isn't yet there, send me a P.M. and specify transfers