Sprite Stitch Board!

i think it's all up to you
as long as it 1. looks good and 2. everything holds together for the wear and tear it's supposed to be exposed to, i think everything is ok.
personally i think the edges will look better with some floss and if the magnet falls off (which it sometimes do) i just glue it back on the plastic canvas. if i would glue right on the threads... think it would be no good. but i've never seen magnetic tape. i use karlssons klister (famous brand in sweden)
but if you don't think people will be close enough to see the backside ('cause one has to be really up close) and the threads will hold together then go for it.

i don't understand this though...

but it doesn't seem to be a strong enough magnet to work if I covered it up with a layer of the plastic.

you mean cover up the magnet with a layer of plastic canvas to hide it completely?
no, don't think a regular small magnet will be strong enough.
and that's not how i do. i don't have a camera right now, so i can't take a picture, but i just glue the magnet on the back like this.

They have magnetic tape on Claes Ohlson artikelnummer 31-3569. I bought it to do something with me sisters kids paintings but then I forgot it. Am planning on doing crosstitch magnets with it for Christmas if it's strong enough.

oh i thought it was som super high tech stuff