Double-Wall Smooth Plastic Caps

A double-wall cap is built in two parts: an inner molding that carries the thread and does the sealing, and a smooth outer shell fitted over it. The outer wall hides the thread, gate marks and functional detail, so the cap presents a clean, uninterrupted surface that looks and feels more substantial than a single-wall cap.

That smooth surface is also an ideal base for decoration. Hot stamping, metallization, soft-touch coatings and custom colors all sit crisply on it, which is why double-wall caps are the standard closure across mid- and high-end skincare.

We supply double-wall caps for skincare and serum bottles, cream and treatment jars, lotions, toiletries and fragrance companions, as well as hair, body and spa ranges. Small sizes from 18 mm suit serum and toner bottles; wide-mouth sizes up to 89 mm close cream jars. Private-label and independent beauty brands use them to give stock glass a branded, finished look without the tooling cost of a fully custom closure.

The inner part is molded in PP or PE with the thread profile matched to the container finish; the outer shell is molded separately and fitted over it. A weighted insert can be added between the walls for extra hand-feel. Bottles are sealed with a foam liner or induction seal, while jars typically use an inner disc. Finishes range from high gloss and matte to metallized and soft-touch, in stock or custom colors.

Match the inner thread to the bottle or jar finish and apply at controlled torque, so the liner or disc seals without the outer shell slipping on the inner. Essential oils and strongly fragranced formulas can attack some coatings and metallized surfaces, so decoration and liner are chosen with the formula in mind. Protect decorated shells from scuffing on the line; tell us your formula type and we’ll recommend a compatible finish.

Inner and outer parts are injection-molded separately, decorated and assembled, with liners inserted and any weighted insert added. Thread fit, wall assembly and decoration quality are our key checks. We color-match the shell to your brand, apply hot stamping, metallization and spray coatings to the outer shell, and supply caps bulk-bagged in cartons with liner and decoration matched to your bottles and jars.