I used 3mm basswood. I used a spare piece of basswood for an old project. I cut with my D1Pro

I glued both pieces together using Loctite super glue gel very little because the resin will act a glue to

on the back side of my project I taped the open see thru holes with resin tape. 

in first bowl of resin mix 

Mix copper mica powder and enough resin to fill seed holes of the sunflower. Put the UV light on Copper resin for one minute

In second mixing bowl put yellow mica powder and enough resin to fill all flower openings thje put uv light on for one minute

in third and forth mixing bowls mix two of the blues in Mica powder both colors in separate bowls add enough resin to fill the rest of the openings. I pour both bowls at the same time to give the sky a very natural look

Put UV light on for 2 minutes.

I then place in the UV light for about ten minutes but the I also put in the direct light so that it will finish curing. It will take 24 hours to completely harden.

I add a 12 inch string and pull string thru three decorative balls then tie off just at the top of the balls to keep them from coming off string the you can hang up anywhere you like