Prepare your workspace. Work in a well-ventilated area on an uncluttered table. Cover your table with newspaper to protect its surface. Put on safety goggles and gloves --- liquid acrylic is extremely harmful to skin and eyes.
Mix the liquid acrylic. Your kit will come with two bottles, one with a curing agent and another with resin. Combine equal amounts of both liquids in a disposable cup and stir with a wooden crafting stick for about a minute until the mixture is well combined and bubbles are gone.
Fill your mold about halfway with the prepared liquid acrylic resin. Set the flower in the resin and gently press it in. Slowly pour more resin around the flower so that you don't disturb the petals. Keep pouring until the flower is completely covered.
Allow the resin to cure and harden. The recommended curing time varies from kit to kit. The usual curing time is between 24 and 48 hours, but some kits only take minutes to dry. Check your kit's packaging for specific curing times.
Remove the cured acrylic resin from the mold. Let the molded acrylic sit in the open air for a few extra hours so that the sides that were inside the mold can fully dry. If you don't allow for the extra drying time, the surface of the acrylic can become smudged with fingerprints.