Common Questions

Acrylic - Cast vs Extruded

Cast (G) vs Extruded (MC) refers to the manufacturing process of sheet making from acrylic pellets, heating, and cooling into the final shape (sheet stock) by either casting liquid into a shape or extruding molten material into a shape.

Cast acrylic (G) is the process of pouring liquid monomer (acrylic in its liquid stage) into a mold shape (sheet, tube, rod, or sculpture) and letting it harden. Each individual piece is casted separately to form the specific shape. Cast acrylic has a higher melting temperature and has a higher tensile strength. Casting acrylic is a more involved manufacturing process and generally more costly than extruded materials. Casted materials have best optical clarity and easier to work with. Best used for general fabrication and thermoforming.

Extruded acrylic (MC) is the process of forcing melted acrylic through a die to form a shape (sheet, tube or rod) in continuous lengths.  The material temperature is well below the liquid state, but high enough where it can be shaped.  Extruded acrylic has a lower melting point and is not as strong as cast material under pressure. Extrusion is a more economical manufacturing process and yields to relatively lower sheet costs.  There are more patterns and shapes readily available in extruded material.  Extruded materials are generally more difficult to fabricate with and higher cutting speeds are needed to prevent edge from melting.

Acrylic vs Plexiglas / Plexiglass / Lucite / Perpex

Acrylic is the generic name of Polymethyl methacrylate (PMMA), also known as acrylic glass, which is a transparent thermoplastic commonly used in its sheet form as a lightweight & shatter-resistant alternative to glass.   

Trade Names / Brands include:

  • Plexiglas® is the trade name for Arkema’s acrylic sheet  ( View Selection ) 
  • Acrylite®
  • Lucite®
  • Perspex®
  • Crylux®

Plexiglas® was the first brand to bring acrylic sheets to market and is the most recognized name in the industry.  Not all acrylic is Plexiglas®, but in recent years “plexiglass” has become a common name when referring to acrylic sheets. Since 1959 we have been an authorized distributor for Plexiglas® and continue to maintain great relationships with all of our suppliers.

*Over the years we have distributed and fabricated with sheets from the manufacturers above.  We have had success with all the major manufactures and they generally perform about the same.  When using imported and unbranded sheets we have had yellowing, defects, and fabrication issues. This maybe caused from the origin of raw materials or manufacturing standards. We appreciate your business and are glad to help you find the material you need.


Opaque vs Translucent vs Transparent

OPAQUE is solid in color and no light transmits through the sheet, thus no background image is visible. e.g. cardboard

TRANSLUCENT is not see-through, but light will transmit through the sheet and have different shades of light coming through depending on the light source in the background. e.g. lamp shade

TRANSPARENT is see-through and you can visually see an image through the sheet.  e.g. tinted glass

Starboard vs Seaboard

Starboard and Seaboard are both “brands” of HDPE marine grade polymer sheets that excel in marine & other demanding environments. They combine the very best qualities of building with wood without any of the maintenance and hassle that comes with the corrosion due to outdoor elements.

Starboard is the “Original Marine Grade Polymer Sheet” manufactured by King Plastic Corporation (data sheet).

Seaboard is manufactured by Vycom (data sheet).

Both are UV rated for continuous outdoor use and are virtually the same when compared side by side.  They share almost identical composition, strength, flexibility, flammability rating, and weight. However, the texture & available colors may vary between the two.  Min Plastics & Supply, Inc. carries the Starboard brand in black or white and are available in 4.5′ x 8′ sheets.

Batch Color Variations

American-made acrylic sheets have very high standards to not have color variations between batches of sheets produced from the same company. There can be a slight color variation between two different companies of acrylic sheets manufactured, yet they work together to keep color variances to a minimum. At times there can be a mismatch in color due to the ratios of dye to monomer. If an exact color match is needed, use the same brand and same batch. All the material needed should be purchased at same time. If you have any questions or need a sample chip please contact us and we will be glad to help you.

Nominal vs Actual Thickness

Nominal = “Approximate or rough dimension by which a material is generally called or sold in trade, but which differs from the actual dimension.” For example, in the lumber industry a standard 2″ x 4″ actually measures 1-1/2″ x 3-1/2″.

Federal government sets thickness standard for the plastic industry where manufacturers have a minimum and maximum thickness tolerances to be considered a certain thickness (nominal).   With today’s technology the manufacturers can produce sheets to within a few thousandths of an inch of each other. With that process in mind manufacturers produce sheet to the minimum thickness the government allows in order to save them tons of material by making thinner sheets.

Nominal vs Actual Thickness:

  • 1/16 (0.625)”     =  .060″
  • 1/8 (0.125)”       =  .118″
  • 3/16 (0.1875)”  =  .177″
  • 1/4 (0.25)”        =  .236″
  • 3/8 (0.375)”      =  .354″
  • 1/2 (0.5)”          =  .472″
  • 3/4 (0.75)”        =  .708″
  • 1 (1.00)”            =  .944″

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