Mold Tech Texture Book

Why are textures important when creating plastic injection molded products or parts?

Creating molds that produce thermoplastic parts with a certain texture is a prerequisite for most products. The texture will be either aesthetic, functional, or both.

Take this DSLR camera, for example:

See the ‘grain’ on the handgrip? This is a texture added to the mold, and you’ll find the same or similar options in a mold tech texture book, each with its own number.

What is ‘texturing’ in terms of plastic injection molding and how is it added to the tooling?

Texturing is where the texture, like the example above, is added to the mold. Such texture may also be called the grain or the pattern. Tooling for molds is commonly made from blocks of stainless steel (by far the most common in China), but may also use aluminum, copper, and other metals. It will start out with no texturing, so the blank canvas for the texture to be added onto is the relevant part of the tooling that requires the texture, such as a handle.

Our senior engineer Paul Adams says this about choosing the right texture:

When approaching a part to add texture to, I always start with a fundamental question: what’s the purpose? Is it purely decorative, enhancing the visual appeal and brand identity? Or does it serve a specific function – like improving grip, preventing glare, or even channeling heat? Answering this question becomes the cornerstone of the design direction.

He goes on to provide further detail:

The first crucial decision is depth and scale: do we want a delicate microtexture or a bold, three-dimensional pattern? Understanding the desired effect helps us identify the most appropriate method, from the precision control of laser etching to the cost-effective versatility of chemical etching.

Pattern and complexity also play a vital role. Simple, repetitive patterns might be perfectly achievable with manual techniques, while intricate geometric designs or organic textures might call for the high-tech finesse of laser micromachining. Choosing the right method ensures the texture is not only aesthetically pleasing but also structurally sound and cost-effective to produce.

Based on your product’s requirements, you can then go on and choose a suitable texture from the mold texture book. (You can learn more about selecting the right mold texture and how they’re added by reading this blog post: Injection Mold Textures: How to Choose the Right One?)

Typically, once the texture has been decided upon, a digital render of the texture will be made and 3D printed. If correct, this render is added to the part of tooling which will be textured, with the remainder masked off to prevent accidental texturing.

Mold texturing methods

To add the texture a mixture of modern and traditional techniques can be used such as:

• Sanding and Polishing
• EDM Spark Erosion
• Media Blasting
• Chemical Photoetching
• Laser Etching

Chemical photoetching, where we etch the texture to the mold in a chemical bath of Nitric acid, is the most popular method today, however, engraving mechanically by hand, media blasting, or even directly engraving by laser can be commonly seen, too. (Paul Adams also discusses the different texturing methods in this episode of our podcast: Mold Texturing: How to Add Desired Finishes to Plastic Parts)

What does a texture book look like?

The book is a collection of slides that show the many textures available and gives them each an identification number.

Here’s an example of the YS texture book, but they all look fairly similar. You can see that the textures available are very diverse, so this book can really help with product design and development:

This video actually shows you what the slides are like and the range of textures in one type of book, the Yick Sang texture book: