BUYER GUIDE / INDUSTRIAL

Thick Sheet vs Thin Sheet Thermoforming: Process Selection Guide

Thick-sheet and thin-sheet thermoforming serve different product categories. Thin-sheet (typically under 1.5 mm) produces blister packs, clamshells and inner trays with fine detail and high cavity counts. Thick-sheet (typically 1.5 mm and above) produces deeper, stiffer, heavier trays for industrial, medical and transport applications. The choice follows product requirements, not preference.

Published and updated: 2026-08-25

Content author: Wenzhou Tonghou Plastic Products Co., Ltd.

04 / ENGINEERING NOTE

Sheet thickness is the starting decision

The forming process, tooling and achievable part are all downstream of the sheet thickness decision.

Thin sheet is drawn to fine detail: tight corners, multiple cavities and light-gauge packaging.
Thick sheet builds rigid, deep structures: industrial trays, heavy-wall containers and reusable transport packaging.
The boundary is not sharp; medium-gauge sheet bridges both categories depending on the application.

05 / ENGINEERING NOTE

Forming method follows material

Thicker sheet needs more than vacuum to distribute material evenly.

Thin sheet can often be vacuum-formed alone, with plug assist for deeper draws.
Thick sheet commonly uses pressure forming and sometimes twin-sheet techniques for hollow sections and high rigidity.
Material distribution in thick sheet depends more on sheet starting thickness and forming method, because stretching is proportionally less.

06 / ENGINEERING NOTE

Match the process to the product

A blister pack and an industrial tray have different requirements; the process should follow, not lead.

Choose thin sheet for retail packaging, blister packs and lightweight inner trays where detail and cost-per-part matter.
Choose thick sheet for reusable trays, deep-draw containers and applications where wall thickness and rigidity are functional requirements.
Some products cross the boundary—confirm the forming method on a representative sample before committing to tooling.

Applications

Blister packs and retail clamshells (thin sheet)
Food, mooncake and electronics inner trays (thin to medium)
Industrial周转 and medical trays (thick sheet)
Deep-draw and heavy-wall applications (thick sheet)

Selection criteria

Required wall thickness and depth
Part size and rigidity requirement
Detail, texture and surface finish
Material type and sheet starting thickness

Pre-production validation

Select the process based on the product requirements: wall thickness, depth, rigidity and detail. Confirm material distribution, surface quality and functional fit on a representative sample before tooling commitment.

04 / DECISION MATRIX

Buyer decision table

Factor	Thin sheet (under ~1.5 mm)	Thick sheet (~1.5 mm and above)
Typical products	Blister packs, clamshells, inner trays	Industrial trays, medical trays, deep-draw
Forming method	Vacuum, pressure or plug-assist	Vacuum and pressure forming, often twin-sheet
Wall control	Sheet thickness, plug design and timing	Sheet thickness, forming method and material distribution
Detail	Fine cavity detail, tight corners possible	Heavier walls, coarser detail, more robust

05 / BUYER QUESTIONS

Common buyer questions

01What thickness range is thin sheet?

Commonly under approximately 1.5 mm, though the boundary is not sharp and depends on material and application.

02Can thick sheet produce fine detail?

Thick sheet can produce good detail with pressure forming, but it will not match the fine cavity definition of thin-sheet blister tooling.

03What is twin-sheet forming?

A thick-sheet process where two sheets are formed simultaneously and joined at the mold, creating hollow rigid structures.

04How do I choose between the two?

Start from the product: required wall thickness, depth, rigidity and detail. The process follows the product, not the other way around.

06 / SOURCE BOUNDARY

Official references

These sources define terminology, testing or acceptance methods. Citing a standard does not claim Tonghou certification and does not replace project-specific validation.

ISO — ISO 2859-1:2026 — Sampling procedures for inspection by attributes

Reference scope：Reference for lot-by-lot acceptance sampling. The drawing, defect classes, inspection level and limits still need buyer-supplier agreement.