Marshall-Gruber Cast Polymer Molds
Superior quality, highly durable production molds for demanding cultured marble, cultured onyx and solid surface cast polymer manufacturing.

No amount of manufacturing ingenuity can take the place of a quality hand-crafted mold for cast polymer manufacturing. Marshall-Gruber Fiberglass Molds are the highest quality, most durable molds available for cultured marble molds and solid surface manufacturing. The integrity of our products is the result of careful procedures and strict controls. All incoming raw materials are tested to ensure that only quality raw materials are used. Quality control inspections are made four times during our production process, with a final inspection made just prior to shipping.

Before ordering a mold, please review these topics related to mold construction options, mold break-in procedures, etc.

Marshall-Gruber offers an extensive selection of high quality standard production molds to fit your cultured marble, solid surface, or other cast polymer production needs:

Bathtub Molds

Select from Oval or Rectangular Drop-In, or from our freestanding clawfoot tub molds for cultured marble or solid surface casting requirements:

Gruber Systems' complete selection of cultured marble bathtub molds and solid surface bathtub molds

Oval Drop-In

Gruber Systems Oval Drop-In Bathtub molds for cultured marble and solid surface casting

Rectangular Drop-In

Gruber Systems Rectangular Drop-In Bathtub molds for cultured marble and solid surface casting

Freestanding Clawfoot

Shower Pan Molds

Shower pan molds from Gruber Systems

Highly durable, superior quality production Cultured Marble and Solid Surface Shower Pan molds available in two basic types - single cavity molds, and "Universal" shower pan molds

Choose from the following series or get help selecting the right series.

1050  |  1051  |  1052

We also offer shower related accessory molds such as
Shower Seats, Shower Ramps, Thresholds and more.

Bowl & Sink Molds

20005 NewportFlair

Hundreds of mold styles to choose from

Floating Bowl Designs

Floating bowls are mounted on custom no-bowl vanity decks to become and integral part of the cast vanity. Bowls can be positioned for any custom installation. All bowl molds are available with fiberglass females, but most bowls also offer reusable and/or permanent hats.

Drop-In Bowl Designs

Drop-in lavatory bowls are also referred to as self-rimming bowls. The drop-in bowl fits through a cut-out in the vanity top. It has a lip or flange that rests on the vanity top holding it in place. In addition to drop-in lavatory bowls, this section includes some drop-in bar bowls.

Other Styles

Explore our other types and styles of bowls and sinks:

Modular Deck Molds

Gruber Systems Modular Vanity Deck or Countertop molds for cultured marble and solid surface manufacturing

Choice of integral bowls and edge styles

Modular vanity decks are used to produce vanity deck castings. All modular models include an integral backsplash, but you can select from your choice of our most popular vanity bowl designs, as well as edge profiles (straight or dripless). If you prefer a vanity deck without an integral bowl, see our line of No Bowl Deck Molds.

Note: Chamfer Edge Cast Modular Deck shown above.

"No Bowl" Deck Molds

No Bowl Vanity Deck or Countertop molds from Gruber Systems

Vanity deck mold without integral bowl mold - just combine with your choice of Marshall-Gruber Floating Bowl Molds

"No Bowl" Deck Molds offer greater flexbility, space-saving and cost savings compared to Modular Deck Molds - in that No Bowl Deck molds do not include and integral bowl or sink. You can purchase a variety of bowl mold separately, and use them with the No Bowl Decks to be able to produce vanities and countertops with a choice of bowl style. Offer your customers more choices, with less invested mold cost using No Bowl Deck molds and our bowl molds. If you prefer a vanity deck mold with an integral bowl mold included, see our line of Modular Deck Molds.

Note: 110 Series No Bowl Deck Mold, 25" wide (110-NB-25) shown above

Wall Panel Molds

Wall panel molds for cultured marble or solid surface casting from Gruber Systems

Note: Cast Slate Tile Panels shown above.

Gruber offers a variety of panel molds – suited to a broad range of uses – including wall panels, shower and bath surrounds, and decorative wall treatments. Molds are intended for cultured marble and other cast polymer manufacturing methods, and include:





TexturedPanel 22737

Textured Panel Mold
Rough, textured surface


Untextured (Smooth) Panel Molds
available in either 3/8" or 3/4"
thicknesses, and in single-cavity or 2-, 3- or 4-cavity models.

Trim Molds

A wide variety of trim molds are available to add value and profit, and make your installations stand out above those of your competition. These molds have a lot of uses - limited only by your imagination!

Sill Molds

Window sill molds have a variety of uses for as trim for windows, fireplaces and other uses, as well as a backsplash for countertop applications. Choose from traditional window sill molds, or corniced sill molds.

Splash Molds

End Splash Molds (aka "Splash Molds) are used to provide raised back similar to a backsplash to the two sides (end) of a deck mold (either Modular or No-Bowl decks). These End Splash molds allow the cultured marble manufacturer the option of utilizing a longer length deck mold for a variety of lengths, and still be able to provide a "sidewall backsplash" to match whatever backsplash height is included in the deck mold.

Bathroom Accessory Molds

Our line includes a multitude of soap dishes, shampoo holders and combination units, shelves, towel bar ends, toothbrush holders, robe hooks, toilet roll holders and more. These items cost very little to manufacture, but can make a huge difference in transforming your customers’ bathrooms from ordinary to truly custom!

By type

Bathroom Accessory Collections

Designer themed collections of bathroom accesory molds for a coordinated bathroom design.

Assorted Molds

Some unique, creative and different mold options for you to add more value and revenue to your business.

Material Demonstration Samples (Shapes)

Oval, Round or Rectangle shapes, some with OG Edge details.

Assorted shape sample molds from Gruber Systems for demonstrating cultured marble and solid surface casting capabilities

Round Shapes

Assorted molds from Gruber Systems for demonstrating cultured marble and solid surface casting capabilities

Oval Shapes

Rectangular shape samplemolds from Gruber Systems for demonstrating cultured marble and solid surface casting capabilities

Rectangle Shapes