What influence does printing have on the selection of different grams of white cardboard?

The selection of white cardboard with different gram weights is centered around three dimensions: printing effect presentation, post-processing adaptability and finished product use scene. The gram weight directly determines the thickness, stiffness and ink absorption of white cardboard, and then affects color reproduction, process realization and durability of finished products. The specific influence can be carried out from four key dimensions:

1. Weight determines the "physical characteristics" of white cardboard and affects the adaptability of printing foundation.

There are significant differences in thickness, stiffness and ink absorption of white cardboard with different grams, and these physical characteristics are the basis for whether the printing can be carried out smoothly and whether the effect can meet the standard.

Thickness and Stiffness: Influence on Printing Smoothness and Equipment Adaptation

Low weight (120-200g): thin thickness (about 0.15-0.25mm), low stiffness, easy to "skew the paper" on the printing machine, so it is necessary to adapt to a high-precision flexo printing machine or a small-size lithographic printing machine (such as a business card printing machine) to avoid overprint deviation (color misalignment > 0.1 mm) caused by insufficient stiffness;

It is suitable for printing "light and thin products" (such as leaflets and seasoning package labels). The finished product is easy to fold and carry, but it is not suitable for making packaging boxes alone (easy to deform).

Medium weight (220-350g): moderate thickness (0.28-0.45mm), moderate stiffness, suitable for most printing equipment (lithographic printing machine, gravure printing machine), stable paper feeding (overprinter deviation ≤0.05mm), so it is the first choice for printing "universal scenes";

Suitable for printing inner pages of picture books, small cosmetic packaging boxes and clothing tags, giving consideration to printing stability and basic support of finished products.

High gram weight (380-600g): thick (0.5-0.8mm) and high stiffness, so it needs to be adapted to a high-pressure printer (such as a heavy-duty lithographic printer) to avoid insufficient ink adhesion ("white exposure");

Suitable for printing "thick texture products" (such as cake boxes and high-end gift box covers). The finished products can be formed independently without pasting, but it takes longer to dry after printing (slow ink penetration).

Ink absorption: affects color reproduction and drying speed.

Low grammage: the fiber density is low, the ink absorption is strong (ink permeates quickly), and the drying time after printing is short (about 10-20 minutes), but it is easy to appear "light color" (ink is absorbed by the fiber too much), so it is necessary to choose high-concentration ink or increase the printing times (for example, red ink needs to be printed twice);

High gram weight: high fiber density, weak ink absorption (ink mostly adheres to the surface), more vivid color reproduction (brand color can be accurately presented), but the drying time is long (about 30-60 minutes), so it is necessary to cooperate with drying equipment (such as UV dryer) to avoid the adhesion of finished products (dirty ink caused by wet ink);

Medium weight: the ink absorption is between the two, without special ink or drying equipment, and it is the best choice for "color balance+efficiency first" scenes (such as conventional packaging boxes and picture books).

Second, gram weight affects the realization of printing process and determines the upper limit of finished product texture.

Different printing processes (such as laminating, bronzing and embossing) have specific requirements for paper stiffness and thickness, and mismatched weight will lead to process failure or finished product defects.

Surface treatment process (film covering, oiling)

Low grammage (< 200 g): It is suitable for "light film" (such as light film and dumb film, the thickness is less than or equal to 12 μ m). If it is covered with thick film (> 15 μ m), it will easily lead to paper curling (the tension of the film is greater than the stiffness of the paper), which will affect subsequent cutting or folding;

Example: 150g white cardboard is used to print the label of seasoning package, which is covered with 10μm light film to prevent oil. If it is covered with 20μm thick film, the label will automatically curl and cannot be pasted flat.

High grammage (> 350 g): it can be adapted to "thick film+special technology" (such as tactile film and laser film), and the stiffness can offset the tension of the film and the finished product is flat; At the same time, it is suitable for "over-thick oil" (such as UV varnish, thickness ≤5μm) to improve the surface gloss, and the over-thick oil on low-grammage paper is prone to "wrinkling".

Medium weight: All basic surface treatments (smooth film, dumb film and common oiling) are universal, so there is no need to worry about tension or wrinkling, and it is the choice of "cost and texture balance" (such as most packaging boxes).

Special technology (bronzing, embossing, die cutting)

Hot stamping/silver stamping: Low gram weight paper (< 200 g) is prone to "bottoming out" (the paper is deformed by hot stamping pressure, exposing the underlying fiber), so it is necessary to reduce the hot stamping temperature (from 120℃ to 100℃) and select thin gold foil (≤ 12 μ m); High-weight paper (> 300 g) can withstand high pressure (15-20 kg/cm), and it is suitable for "ironing thick gold foil" (> 15 μ m) or "three-dimensional bronzing" (embossing texture), with more outstanding texture.

Bump/dent: the paper should have enough thickness to support "deformation", and bump with low grammage (< ＜220g) is prone to "rebound" (the bump shape cannot be set), while bump with high grammage (> ＞250g) is stable in shape (for example, 300g white cardboard can be used to print business cards, and the bump logo can maintain the three-dimensional effect for a long time).

Die-cutting: low-weight paper die-cutting is easy to "stick to the knife" (loose fiber leads to corner adhesion), so it is necessary to clean the knife frequently; The die-cutting edge of high-weight paper is smoother (the fiber is tight), but a high-hardness die-cutting knife (such as a tungsten steel knife) is needed to avoid the blade from wearing too fast.

Third, the weight matches the "finished product use scene" to determine the practicality of printed matter.

The final use of printed matter (such as packaging, business cards, picture books) has clear requirements on durability and form, and the weight should be adapted to the needs of the scene to avoid "insufficient function" or "excessive waste".

Packaging printed matter: gram weight determines protection and form

Inner packaging/light packaging (such as snack inner bag and digital accessory box): choose 180-250g, giving consideration to printing color and mild protection (anti-extrusion, anti-scratch), and the cost is moderate;

Example: 200g white cardboard printed earphone packaging box, with brand pattern printed on the surface and separated by cardboard inside, is light and can protect the earphone from shaking.

Independent packaging box/gift box (such as cake box and cosmetic gift box): choose 300-450g, which is stiff enough to support the independent molding of the box body (without corrugated mounting), and can bear the processes of bronzing and embossing to improve the texture;

Example: 350g white cardboard is used as a birthday cake box with bronzing pattern on the surface. The box body can stand without additional support, and the bearing capacity is ≤5kg (cake+tray weight).

Heavy-duty packaging/composite packaging (such as household appliance accessory boxes and gift boxes): choose 400-600g, or compound with corrugated paper (corrugated with white cardboard). High-gram heavy white cardboard enhances the texture of printed surface, and corrugated enhances the pressure resistance;

Example: 450g white cardboard is corrugated to make microwave oven accessory box, the outer layer is printed clearly, and the inner layer is corrugated to prevent transportation extrusion.

Printed matter/creative category: Gram weight determines handle and durability.

Light and thin category (leaflet, greeting card inner page): choose 120-180g, which is easy to fold and portable, suitable for mass distribution or mailing (reducing logistics cost);

Example: 150g white cardboard is printed with promotional leaflets, which are bright and light, and 100 pieces only weigh about 150g, so the mailing cost is low.

Texture category (business card, album cover, tag): choose 250-350g, which feels thick (for example, the thickness of 300g business card is about 0.4mm), and it is resistant to flipping and breakage, suitable for long-term use;

Example: 300g white cardboard is printed with high-end business cards, and the surface is covered with matte film, which has a delicate feel and is not easy to deform after repeated storage.

Three-dimensional category (cultural and creative ornaments, handmade boxes): choose 380-600g, which has high stiffness and is easy to shape, and can be directly folded into a three-dimensional structure (such as storage boxes and decorative ornaments) without glue or brackets;

Example: 500g white cardboard is made into a manual storage box, which can be formed after cutting and folding. It is stiff enough to support the box body and can hold small stationery (weight ≤1kg).

Fourth, weight is related to "cost and efficiency", which affects the printing economy.

The purchasing cost and processing efficiency of different grams of white cardboard are quite different, so it is necessary to balance "effect" and "cost" to avoid excessive investment.

Cost level: the higher the grammage, the higher the unit price (for example, 150g white cardboard is about 5 yuan/ream and 350g 12 yuan/ream), and the high grammage paper needs more ink (weak ink absorption, thick surface ink layer) and long drying time (need to increase the energy consumption of drying equipment), and the comprehensive cost is about 2-3 times that of low grammage paper;

Example: Printing 10,000 leaflets, choosing 150g to save paper cost by about 70% compared with 300g, and saving ink and energy cost by about 40%.

Efficiency: Low-weight paper has a fast paper feeding speed (the speed of lithographic printing machine can reach 15,000 sheets per hour), while high-weight paper has a slow paper feeding speed (about 8,000 sheets per hour) due to its high stiffness and thickness, and the equipment pressure needs to be adjusted frequently, so the production efficiency is about 40% lower;

Example: mass printing of clothing tags (100,000 pieces), and selecting 250g saves about 1.5 days of production time compared with 400g.