For this collage i used special variants of four snowflake photos. When processing each snowflake, i draw by hand precise mask, which separates crystal from background (i need it for processing object and background with different sharpening and noise removing settings). Drawing these mask is time consuming work, and requires lots of patience; but automatic methods of edge selection, which i've tried, do not provide enough quality. Now masks was used to blur background around snowflakes.
I'm not sure that these variants are good, though, because original background is visible through transparent crystals. You can see original snowflake photos: Rigel, Leaves of ice, Alioth and Vega on unchanged background.
You can see visual difference in size of crystals in this collage, and it is real: all four snowflakes was captured at same distance from the lens and with fixed magnification, and i do not re-scaled photos on post-processing stage.
Prints available at: Artist website, RedBubble.com.
This is bigger variant of collage, twice wide and tall:
Prints available at: Artist website, RedBubble.com.
If you want to see more snowflakes, you can browse through all snowflake pictures.
Here you'll find snowflake photo wallpapers in numerous resolutions and screen proportions, up to Ultra HD 4K.
And here is article about snowflake macro photography.