Black Paper is a type of sturdy and thick colored cardboard that is dyed inside and outside of the paper to appear black. The conventional weight is generally 70 to 750g, with a thickness specification of 0.7-1.0mm

Meaning and Classification

Black Paper belongs to thick paper with a relatively large basis weight (usually above 120g/m ²), corresponding to white cardboard. According to the raw materials and degree of transparency, it is mainly divided into categories such as all wood pulp Black Paper (neutral and environmentally friendly), double-sided transparent Black Paper (double-sided same color), single-sided transparent Black Paper (front black back light), and gray base single Black Paper (one side black and one side gray).

Raw materials and processes

Raw materials: Mainly made of wood pulp (a mixture of coniferous wood pulp and broad-leaved wood pulp), with some products using recycled waste pulp. Dyes usually use environmentally friendly dyes such as direct black G, combined with additives such as sodium sulfate (dye promoter) and cationic starch (retention aid).

Core process: The key lies in dyeing inside the pulp. Adding dyes to the pulp before or during the pulping process to color the fibers as a whole and achieve "transparent black", rather than just coating on the surface. After copying, surface sizing, dyeing, and calendering treatment are usually carried out to improve surface delicacy and glossiness.

Simple technical indicators

The following data is from some patent literature and can be used as a reference. Actual indicators vary depending on the product grade:

Moisture content: 6%~12%

Tightness/bulk density: approximately 0.72~0.76 g/cm ³

Burst index: 2.60~2.88 kPa/g

Ring compression strength index: 7.1~8.7 N · m/g

Smoothness: 9-15 seconds

Characteristics

Appearance and texture: The paper is delicate, the blackness is uniform, there are no white spots on the surface, and the middle sandwich part of the double-sided transparent black is also black.

Physical properties: firm and thick, good stiffness, high folding resistance, smooth surface, strong tensile strength, high durability.

Environmental Protection and Safety: High quality all wood pulp Black Paper is usually neutral, uses environmentally friendly dyes, is recyclable, and does not contain harmful substances such as chlorine, volatile sulfur, organic benzene, etc., meeting the metal element limit requirements for packaging materials.

Usage

Packaging field: widely used in high-end packaging such as gift boxes, jewelry boxes, cosmetics boxes, shoe boxes, mobile phone boxes, tea boxes, as well as clothing tags and handbags. Gray bottom single Black Paper is commonly used for photo frame backboards and gift boxes.

Cultural supplies: used for photo albums, frames, puzzles, folders, notebook covers, calendars, and book binding.

Special purpose: The electroacoustic Black Paper is specifically used as a gasket for speakers; High opacity Black Paper can also be used for special packaging such as instruments and chemicals that require light avoidance.

Black Paper stands out in the world of paper due to its pure color and solid texture. It not only carries the practical function of packaging, but also endows the design with a calm and restrained aesthetic expression. From high-end gift boxes to cultural creativity, from industrial pads to artistic binding, Black Paper silently supports countless scenes that require "black power" with diverse weights and specifications. Choosing Black Paper is not only about choosing a material, but also about injecting a low-key and confident texture into the work - in the silent place, it fully displays its style.