I decided to test the Hahnemuhle Protective Spray against Lukas Spruchfilm UV 2321 Gloss UV protect spray (400ml) and against some Kiwi generic spray I had at hand (just for fun). As a dye ink photo printer using the HP T120 a lot, a UV stable protective spray can be essential to guarantee colorfastness and water tightness for prints that need that (outdoor use etc).

In short:

The Kiwi spray is horrible on the tested HP Premium Gloss paper, which makes sense as it is not designed for paper but more likely leather. The Hahnemuhle Protective Spray has no marking of satin or gloss but I would say it sits right in between satin and gloss (semi gloss?). The Lukas Spruchfilm UV 2321 Gloss UV protect spray is marked as gloss and indeed clearly shows gloss on the print. See samples below.

The Lukas spray does a good job although the Hahnemuhle Protective Spray seems to dry slightly better and with less bubbles. I do, however, much prefer the gloss of the Lukas spray. Dus is your worst enemy when using these sprays. You can clearly see that on the Lukas gloss spray sample above. If you make sure that all bubbles are sprayed over again during application, you can get a relative clean layer of coating using these spray. The Lukas spray should give good protection against UV and water. I have not tested it long enough to be able to tell you something about the UV protection (which is not much of a problem with the HP T120 on HP Premium (Plus) paper but is on any other paper, but I have tested water. Surprisingly, it holds against water really well. In fact, of all sprays I have tested so far (see here for my test of Lascaux UV Protect) the Lukas spray seems truly water tight!

So if gloss and or watertightness is critical for your HP T120 or HP T520 prints you can use Lukas UV Gloss Spray. However, you will probably see some dust particles being varnished in your spray coating as well (and those will be somewhat visible if standing close to the print). The good news is further that the Lukas Gloss Spray 2321 UC is much cheaper than the Hahnemuhle Protective Spray so for me it is a no brainer.

If you are you  printing with a dye ink based printer, make sure you test this Lukas spray!