When making test holograms with Liti's photopolymer that comes pre-mounted on glass, I found that it was very hard to store finished holograms safely without attracting scratches and dust. And worse, a lot of them would start peeling off of the glass, getting dust to the emulsion's surface. So I started trying out a number of laminates available at local stores, but all of them would ruin the image and shift the colors. (Red -> Green, Green -> Blue).
I skimmed through Practical Holography 5th Ed. again looking for solutions and found the following: (p. 324, "Preserving the Color in Color Holograms"):
I had a look and it seemed like 3M's 9483 laminate had to be custom ordered, so I never got around to trying it out. But one day, I was at a dollar store in Japan and found these cheap 5.2"/5.5" glass lcd screen protectors meant for smartphones, and I thought that's it! So I tried it out immediately.Once you have exposed and processed your hologram, seal it against the ingress of any moisture. Laminate films to plastic or glass, emulsion down. Note that certain laminating materials may bond with gelatin or photopolymer and may change the color balance, and at worst even destroy your holographic image. [...] For silver halide film, Geola recommends 3 M 9483 optically clear laminate adhesive or similar products.
I simply sandwich the exposed photopolymer between two glass screen protectors of the same size. It looks like the laminate used is non-abrasive, since I don't see any color shifting, and because it's glass the image is nice and clear.