How do I embed or suspend objects at a set depth in a Deep Pour or mold casting?

Use UltraClear Deep Pour Epoxy and build the casting in layers. Pour the first layer at the depth you want the objects to sit, anywhere from 1/4" to 1", wait 12 to 24 hours, set your items on that layer, then pour the next layer 12 to 24 hours later. Keep adding layers of up to 1" every 12 to 24 hours until you reach the final depth. Every layer must be at least 1/4" thick or it will not cure properly; pouring thinner 1/4" layers gives you finer control over where things sit.

Finding the right moment to place objects is something you learn by testing. A layer is still tacky within the 12 to 24 hour recoat window, but the gel stage comes sooner or later depending on room temperature and how much epoxy is in the pour: small batches take longer to gel, large batches gel faster because they build more heat. Do a few small test pours to find the point where items hold without sinking before you commit to the full project.

Seam lines between layers are not normally noticeable when you recoat within the window, and adding color blends them further. For an even color through a deep casting, measure the pigment in your first batch and use the same amount in every layer.

To keep bubbles down, mix gently (a stir stick by hand for batches under a gallon) and pour each layer in 1/4" increments so you can pop bubbles as you go.

For thin pieces, such as pressed flowers under a 1/8" layer, UltraClear Bar & Table Top Epoxy works well and is what many experienced creators use. For dried flowers in a 4" to 5" deep mold, use Deep Pour in 1" layers as above.

Deep Pour Epoxy instructions: https://ultraclear.helpscoutdocs.com/article/840-deep-pour-epoxy-instructions