Coverage for 1/2 mm tiny glass marbles (not the same for larger marbles):

4 ounces - about 3/8 cup
(1/2 mm size covers approximately 1.5 square feet - area 1' x 1.5')
8 ounces - about 3/4 cup
(1/2 mm size covers approximately 3 square feet - area 1' x 3')
1 Pound - about 1 1/2 cups
(1/2 mm size covers approximately 6 square feet - area 2' x 3')

You get far less coverage from larger sizes. 2mm micro marbles coverarge is about 1/3 of the coverage you get from 1/2 mm micro marbles.

Lightfast Qualities - Ability to keep color under UV and Florescent Lighting

Semi-transparent glass micro marbles: lightfast, holds color over time
Metallic coated glass micro marbles: not lightfast, fades with light and time

We have tested these in a sunny window, nothing scientific. The glass ones appear to actually be made from colored glass, instead of coated with something.

We have tested multiple sources of these as well those carried by our competitors and all the craft metallic micro beads on the market that we've found are not lightfast. We found a source that makes lightfast ones for clothing, but the colors are dull and they cost quite a lot more. The metallic ones all fade rather quickly to silver and then a tarished silver. There are UV protective sealers available if your project needs to hold up outside or for a long period of time inside.

Ways to adhere micro beads or micro marbles:

• Red Liner Tape - clear double sided, super tacky tape. This tape does not lose its tackiness over time, but if it will be exposed to a lot of handling, we recommend using clear glass sand to fill in the exposed tape between beads.
• Sticky embossing powder - this is heat activated glue powder. Use it like you would embossing powder, over an image stamped with slow-drying or embossing ink. When heated with a heat tool, the glue powder turns to a liquid glue that dries as it cools.
• Liquid glues - jewelers glue or glue that dries clear and hard and permanent (doesn't remoisten). E6000 is quite strong and permanent, but you might also try Diamond Glaze if you find the E6000 hard to work with.
• Tsukineko's Essential Glue Pad - you can stamp an image with the glue pad and pour micro marbles over it. The glue, itself, isn't strong enough, even when dry, to hold micro marbles, except just enough to hold them in place while not being touched. By melting superfine embossing powder between the beads that are clinging to the glue pad ink, you have a fairly strong hold for card making or scrapbook embellishments. You need to seal it with additional protective top coats if your project will be handled much and needs to be permanent.