Here you are ....
1) Take some paper (e.g. strong brown) and cut to the size of the diamond shown in the pdf attached to this post.
2) Fold first along the lines S & G, then along R & C.
3) Unfold, put seeds where our logo is, and repeat the folding.
4) Stick a white label, the size of the address label on the Seed List envelope, over the folds.
5) Write the full taxon name clearly in black on the label, your name (smaller) at the bottom.
You could perhaps prepare the white labels and print them with your computer....