Decorating Blow Molded Parts

With so many blow molded products on the market, it isn’t surprising that there are dozens of ways to decorate them. Here are some examples.

Engraving & Texturing

Engraved logos, text or icons are cut into the mold and will be present in every part with no added cost.   Most black & white images can be engraved and reproduced on a part’s surface.  Inserts can be designed into the mold to allow changes or to test smaller options.

Texturing allows large surfaces to have a consistent, high quality appearance.

Labels & Plaques

Labeling is a very popular way to introduce color at a low cost.   Labels are available for post-mold or in-mold applications.

Post-mold labels are usually available in the same plastic material as the molded parts, making recycling easy.

In-mold labels need to have substrates and adhesive layers that work with the desired plastic for the in-mold application.

Plaques offer pre-printed raised lettering for an enhanced 3D look.   Plaques are often designed to attach mechanically with barb or snap features making adhesive selection unnecessary.

Printing, Painting and Powder Coating

Traditional printing processes like Lithography or rotogravure are used on plastic sheet but not on molded parts because of their shapes.  Pad, roll, silk screen, or stencil printing are more common for molded parts.

Plastic materials are seldom porous or absorbent so getting your inks to adhere usually requires surface preparation.  Some plastics are pretty easy to print or paint such as ABS, PPO (Noryl), Polystyrene & Acrylic.

Very few ink or paint formulations are made specifically for blow molded olefins (Polypropylene, Polyethylene).

Wildlife decoys, lawn statues and holiday decorations are normally painted and often require 2-part paints and extensive surface preparation. Clarity of the printed image requires continual monitoring of ink & solvent ratios to maintain the proper viscosity.  Testing to verify your ink can be removed for re-printing is advised.

Success with powder coating plastic parts is again, plastic resin dependent.  Plastics that readily accept a static charge can be coated easier than plastics like PE & PP that act as insulators.

Heat Transfer & Hot Stamp

Transferring color onto a part using heat and pressure is a common practice.  Heat transfers typically use a press with an engraved die to melt a section of colored film onto the part.  The die shape creates the colored area.  Hot stamping normally uses a press with a heated plate to apply a full color label.

Heat Shrink Wraps and Sleeves

Pre-printing heat shrink films for die cutting and applying decorative bands to parts as they come out of the mold is popular with high volume production clients.    Set-up can be costly but per-unit prices are generally low.  The wraps quickly grip most shapes and are easily replaced if a problem occurs.


For more information on decorating blow molded products you can contact our technical sales staff.