Laminated object manufacturing (LOM) is a 3D printing method that builds objects by stacking and bonding thin sheets of material, then cutting each layer to shape with a laser or blade. Developed in 1991 by a company called Helisys (later succeeded by Cubic Technologies), LOM was one of the earliest rapid prototyping technologies and remains one of the fastest and least expensive ways to produce physical models from digital designs.
How the Process Works
LOM starts with a roll of sheet material, typically paper, plastic, or metal-filled tape, pre-coated with a heat-activated adhesive on one side. The machine feeds a fresh sheet from the roll onto the build platform, where a heated roller passes over it, pressing and melting the adhesive to bond the new layer to the one beneath it.
Once the layer is bonded, a laser or knife traces the outline of that cross-section based on the 3D CAD file. Here’s where LOM differs from most other 3D printing methods: the laser also cross-hatches the surrounding material (the part that isn’t part of the final object) into a grid of small blocks. These blocks stay in place during the build, acting as structural support, but they’re designed to be peeled or broken away once printing is complete. The platform then lowers by one layer thickness, a new sheet rolls into position, and the cycle repeats.
Layer thicknesses typically range from about 0.1 mm to 0.2 mm, depending on the material. Because each layer is a full sheet rather than a thin trace of melted filament or cured resin, the process can cover large areas quickly.
Materials Used in LOM
The original and most common LOM material is adhesive-coated paper, which produces parts with a wood-like look and feel. Paper-based parts can be sanded, painted, and even machined much like actual wood, which makes them popular for visual prototypes and architectural models.
Beyond paper, LOM systems can work with polymer composites, ceramics, fabric materials, and metal-filled tapes. Metal and ceramic sheets are used less frequently but open the door to functional parts and tooling applications. The key requirement for any LOM material is that it comes in thin, uniform sheets and can accept a heat-activated adhesive coating for bonding.
What LOM Is Used For
LOM is primarily a rapid prototyping technology. Its sweet spot is large, solid models with relatively simple geometry, where speed and low cost matter more than fine detail. Think architectural scale models, concept mockups, and visual aids rather than precision-engineered components.
One area where LOM found a strong niche is foundry work. Because paper-based LOM parts behave like wood, they can replace traditional wooden patterns used in sand casting, wax injection molds for investment casting, and master models for silicone molding. This can significantly cut the time and cost of producing casting tooling, especially for complex shapes that would take a skilled patternmaker days or weeks to carve by hand. LOM is best suited for compact models with complex outer geometry but without many fine details or deep undercuts.
Accuracy and Dimensional Tolerances
LOM machines typically claim an overall dimensional accuracy of ±0.25 mm, with roughly 2% expansion in the vertical (Z) direction due to adhesive compression and thermal effects. In practice, those numbers aren’t always achieved. Independent testing has found that dimensional deviations can reach 0.5 mm to 0.9 mm in worst-case scenarios, with average deviations often exceeding the claimed ±0.25 mm spec.
External features tend to hold tighter tolerances than internal ones. In one study, external circular features deviated by about 0.15 mm on average, while internal features averaged closer to 0.16 mm. Along diagonal axes, deviations climbed higher, sometimes exceeding 1 mm. This means LOM parts are suitable for form and fit checks but generally not for applications requiring tight mechanical tolerances.
Advantages Over Other 3D Printing Methods
Cost is LOM’s biggest selling point. Paper is cheap, and the process doesn’t require expensive lasers powerful enough to melt metal powder or UV-curable resins. For large parts especially, LOM can be significantly faster than methods like stereolithography (SLA) or selective laser sintering (SLS), because the laser only needs to trace outlines rather than fill entire cross-sections.
Waste material from paper-based builds can often be recycled, giving LOM an environmental edge over processes that generate non-recyclable support structures. The finished parts also have a unique aesthetic quality: paper LOM objects look and feel like laminated wood, which can be desirable for presentation models without any painting or coating.
Limitations to Be Aware Of
Part strength is the most significant tradeoff. Because LOM parts are held together by adhesive bonds between layers rather than being fused or cured as a solid mass, they’re weaker than parts made by SLS, SLA, or fused deposition modeling (FDM). They can delaminate under stress, and moisture can degrade paper-based parts over time.
Post-processing is another pain point. Removing the cross-hatched waste material from around and inside the finished part is a manual, labor-intensive step. For parts with internal cavities or complex internal geometry, this “decubing” process can take longer than the print itself. Surface finish tends to be rough due to the visible layer edges, and smoothing requires additional sanding or sealing. Dimensional accuracy, as noted above, lags behind most competing technologies, which limits LOM’s usefulness for functional parts or anything requiring precise fits.
How LOM Compares to Other 3D Printing Technologies
- Speed: LOM is generally faster than SLA and SLS for large, bulky parts because the laser only traces contours rather than scanning entire surfaces.
- Cost: Material costs are lower than resin-based or powder-based methods, especially when using paper. Machine costs are also typically lower.
- Part strength: Weaker than FDM, SLS, and SLA parts due to reliance on adhesive bonding rather than material fusion.
- Accuracy: Lower dimensional precision than SLA or SLS, making it less suitable for functional prototypes with tight tolerances.
- Material range: Broad in theory (paper, plastic, metal, ceramics), but fewer commercially available material options compared to FDM or SLS ecosystems.
LOM occupies a specific niche: it’s the go-to choice when you need a large, inexpensive physical model quickly and don’t need it to bear loads or fit precisely with other components. For visual prototyping, foundry patterns, and concept validation, it remains a practical and cost-effective option in the additive manufacturing toolbox.