Grid Chalkboard Steel Coil
The surface of the Grid Chalkboard Steel Coil features a functional coating—a paint specifically designed for chalkboard steel sheets. The substrate is typically galvanized steel coil, and the sheet structure consists of a base sheet, primer, topcoat, grid printing, and clear coat. The finished product is delivered in coil form but can also be uncoiled and cut to size upon customer request.
Ensure product quality and transportation
Based on surface application, this type of material mainly comes in three series:
- White base with black grid lines, for whiteboard marker writing;
- Green base with white grid lines, for traditional greenboards;
- Black base with white grid lines, for blackboards, menu boards, and decorative panels.
The substrate and coating structure are the same for all three series; the differences lie in the topcoat color, gloss, and grid line color. Therefore, the same production line can switch between series based on orders.
Specifications
| Product Name | Grid black steel coil, Grid white steel coil, Grid green steel coil |
| Thickness | 0.09—1.0 mm |
| Common Thickness | 0.10 / 0.20 / 0.25 / 0.30 / 0.35 / 0.40 mm |
| Width | ≤1300 mm |
| Common Width | 1000 / 1200mm |
| Substrate | Galvanized steel coil (GI), cold-rolled steel coil, tinplate can also be used |
| Zinc coating | 30–275 g/m² |
| Paint Coating Type | Polymer resin topcoat >3H hardness, epoxy primer, specially designed for adhesive/core material bonding |
| Paint Coating Thickness | Topcoat 15-25um; Backcoat 5-15um, customizable |
| Coil Inner Diameter | 508 mm / 610 mm |
| Coil Weight | Commonly 2.5—3 t, customizable according to customer’s uncoiling equipment |
| Gloss (60°) | 30—90 GU; Matte ≤15 GU |
| Pencil Hardness | ≥3H |
| Coating Adhesion | Cross-cut test 0—1 grade |
| Scrub Resistance | ≥50,000 times |
| Soluble Resistance | ≥100 wipes |
| Neutral Salt Spray | ≥72 h Rust-free |
| Grid Size | 5×5, 2×2, 1.25×1.25 cm and custom sizes available; line width 0.5-1.5 mm |
| Protective Film | Transparent film / Blue film / Printed film |
| Packaging | Export standard packaging: moisture-proof paper, plastic film, sheet metal, wooden pallet |
| MOQ | 10 t |
| Certifications | ISO9001, CE, SGS |
Production video
For more videos on the production and testing of magnetic writing steel plates, please check out our YouTube channel.
Differences from Standard PPGI Steel Coils
While standard PPGI steel coils are only required to meet specifications for color, corrosion resistance, and weather resistance, the writing surface material has three additional requirements compared to standard PPGI steel coils.
- An additional grid printing and topcoat process is applied, with the lines enclosed by the outermost layer of varnish to prevent the printed layer from being worn away during erasing.
- The topcoat resin is formulated specifically for writing applications, with controlled gloss, surface tension, and stain resistance to ensure smooth writing with both chalk and whiteboard markers and clean erasure.
- Factory inspections include two additional practical tests: actual writing and erasing, as well as observation of residue after repeated wiping.
It is precisely these three levels of difference that account for the main variation in the prices of materials of the same specifications.
Color and Grid Line Color Schemes
The three background colors are not merely different shades; they also feature different writing media, gloss levels, and grid line colors. The table below shows the standard configurations:
| Color | Grid Line Color | Surface Gloss | Writing Media | Typical Applications |
| White (Titanium White, Cream White) | Black or dark gray | Semi-matte to matte; high-gloss options are also available | Whiteboard Markers (Dry-Erase) | Office whiteboards, training whiteboards, children’s drawing boards |
| Green (Educational Green) | White or black | Matte, ≤15 GU | Chalk | School blackboards, teaching boards |
| Black (Matte Black) | White | Matte | Chalk | Blackboards, menu boards, decorative boards |
Grid Specifications and Customization
| Specifications | Cell Size | Applications |
| Standard Grid | 5 cm × 5 cm | Classroom partitioned board writing, meeting whiteboards |
| Fine Grid | 2 cm × 2 cm | Math calculations, pinyin practice, early elementary education |
| Extra-Fine Grid | 1.25 cm × 1.25 cm | Fine motor skill practice, chart creation, coordinate-based board writing |
| Large-Character Grid | 10 cm × 10 cm | Preschools, early childhood education, large-character demonstrations |
| Custom Options | T-grid, cross-grid, four-line-three-cell grid, etc. (according to customer drawings) | Chinese character writing and structure instruction, Chinese language schools, calligraphy practice |
Who Should Purchase These Products
- Manufacturers of finished blackboards and whiteboards, especially those supplying schools and training institutions, where order specifications are diverse but individual batch sizes are small;
- Educational equipment exporters and general contractors who need to assemble board surfaces, aluminum frames, and pen trays according to project drawings;
- Manufacturers of chalkboards, calligraphy practice boards, and children’s drawing boards;
- Office furniture and partition manufacturers who use grid-patterned board surfaces for meeting areas and bulletin board zones.
Wanzhi Steel: Writing Steel Sheets Professional Manufacturer
We strictly adhere to our testing procedures. Routine factory inspections are conducted as outlined in the table below. Customers may also request a re-inspection by a third-party organization (such as SGS; you can also download the SGS test report for our magnetic writing steel sheets).
Our routine tests include: writability, adhesion, pencil hardness, wipe resistance, solvent resistance, salt spray resistance, coating thickness, gloss, color and color difference, and flatness.
Wanzhi Steel has over 15 years of production experience and has exported to more than 120 countries. We can produce steel sheets as thin as 0.09 mm to meet a wide range of customer needs. If you are interested in purchasing magnetic writing steel coils, please feel free to contact us at any time.
