This guide will be helpful if you run an aligner lab or plan cases as a dentist.  

Single layer aligner sheets are made of a single plastic. Multi-layer aligner sheets are typically 3 layers, with 2 firm layers and a soft middle layer. Multi-layer sheets have been shown to provide reduced and more consistent forces than single layer sheets in lab testing [1,2].  

The choice between single and multi-layer sheets can depend on many factors such as the amount of movement required, the stage of treatment, and how the trays are thermoformed. Let’s learn more about it and get quick guides to help you decide. 

Understanding Single and Multi-layer Sheets 

Single layer sheets are like one slice of bread! Multi-layer sheets are two firm slices with a soft filling in the middle to provide a balance between firmness and comfort [3]. The most common materials used are PETG (known for clarity and flexibility) and TPU (known for elasticity and durability) [4]. 

However, not all multi-layer sheets are created equally. According to a study, 9 sheets were tested independently with thickness between 0.7 and 0.8mm. The stiffness of the sheets ranged from 1394MPa to 2671MPa. Concluding, 

• Single layer sheets showed similar levels of flexibility [3]. 

• Multi-layer sheets had the lowest stiffness (1394MPa and 1538MPa).  

Pro tip: A technical data sheet for your specific sheet and thickness is needed. Just because a sheet is described as multi or single layer doesn’t mean you can determine the stiffness. 

The Force Story: Why Layers Change What Teeth Feel 

All sheets will experience some elastic relaxation (like when you stretch a rubber band, and it slowly relaxes). This can be over 50% of initial force in the first few hours [2]. Multi-layer sheets are just gentler in that way.  

Multi-layer sheets provided 30-45% less force than single layer sheets (calculated from published figures) [1]. 

In lab tests	Single-layer sheet	Multilayer sheet
Active force on a model incisor	131.9–149.7 N	83.1–92.5 N
Stress compared with single layer	Baseline	Up to 4× less
Force over 24 hours	Rapid decrease	Slow and even release

Thicker sheets will provide more force. 0.75mm sheets provided a clear increase in force compared to 0.50mm sheets made from the same material [1]. When comparing sheets, ensure they are the same thickness.  

Pro tip: When trying a new sheet, only change 1 factor. Keep the thickness and the case type the same, so any difference you see comes from the sheet and not from something else. 

From Sheet to Tray: Thermoforming Notes for Your Lab 

Both sheets will thermoform quite well, using the correct settings. However, thermoforming will change properties of the sheet [7]. In a micro study looking at 6 aligners of the same nominal thickness, there was variation in the thickness across the arch [8]. To help with this try to: 

• Follow the correct heating/cooling settings for the sheet. These will vary depending on sheet and thickness. 

• Ensure the sheet is compatible with your machine. 

• Measure the thermoformed tray in a few areas (incisors, premolars, and molars). 

• Keep a log of your settings for each case, so you can compare results over time. 

We have an Instruction for Use page and a compatible machines list to start from. 

Pro tip: When starting to thermoform a new sheet, create a sample tray. Measure the thickness of the tray at incisors, premolars, and molars using a thickness gauge. Allow the tray to cool for the correct amount of time as stated in the instructions before trimming. 

Case-Matching Cheat Aligner Sheet 

When choosing an aligner sheet for your case, consider what movement you require. The table below is a starting point based on lab and simulation studies. This is not a clinical rule; however, this will help you with the judgement first. 

If you need…	Consider	Why
Gentle and consistent force in early stages	Multilayer	Reduced force and even release
Bodily tooth movement	Thicker single layer	Higher force in lab tests [1].
Front-teeth retraction	Generous multi-layer sheet	With >50% soft layer a simulation showed improved movement and reduced ligament stress [9].
Different needs in different phases	Alternate both	One lab study suggests this may be a good option. Clinical evidence is required [1].

Five Questions to Ask Before Choosing an Aligner Sheet 

 This is a practical guide, which will be a definite help for the judgement. 

1. What is the main movement required? Gentle staging leans multilayer aligner sheet. 

2. What thickness will you thermoform? Thicker sheets will produce more force. 

3. What is the data saying for your specific aligner sheet? Don’t assume based on just the layer. 

4. Is your machine compatible? 

5. How will you check your thermoformed tray? 

Pro tip: Print off this list or you can add these questions to your case form. 

Summary of Taglus Sheets 

Taglus offers sheets for aligners, mainly PU Flex, Premium, and Standard.  

In the independent lab study in 2026, Taglus PU Flex was the stiffest sheet (2671MPa) out of 9 sheets. Taglus Standard had a stiffness of 2112MPa. All sheets showed slight changes after 14 days in artificial saliva [3]. 

Aligner sheet	Material	Properties
Taglus PU Flex	Polyurethane	Great flexibility, about 20% more initial forces compared to other sheets.
Taglus Premium	PETG	Ultra transparent sheets, best mechanical properties.
Taglus Standard	PETG Copolyester	Dual protective masking,

 Pro tip: Before changing your entire workflow, try a new sheet on a few typical cases. Ask the Taglus team about trialing options. 

FAQs 

Which aligner sheet is more effective, single-layer or multilayer? 

Neither sheet has been shown to be more effective. Multi-layer sheets provide reduced and more consistent force, and single layer sheets provide higher force in lab testing. There is little clinical data so choose based on the planned movement and stage of treatment. 

Do multi-layer sheets move teeth faster? 

Not necessarily. One small, blinded study found that 73.1% of planned movement was achieved compared to 42.8% on day 14. However, there was no significant difference in expansion accuracy in a study looking at 65 patients. Both studies looked at the complete system. 

What thickness of aligner sheet should I use? 

Always follow the guidelines provided by the sheet manufacturer. Many studies look at sheets around 0.75mm. This shows a clear increase in force compared to 0.50mm sheets made from the same material. Thicker sheets are better for cases requiring more force. 

Can I use the same thermoforming machine for both sheets? 

This depends on the machine and sheet. Each sheet will have specific heating/cooling settings. Firstly, check the compatibility list provided by the manufacturer. Taglus has a list available. 

Do aligner sheets change while being worn? 

Slightly. A review of 14 studies in 2026 found all materials tested were affected by intraoral wear [10]. This is why treatment plans have set wear times for each stage. 

Can I use single and multi-layer sheets in the same case? 

One lab study suggests alternating sheets in the same phase. This may be useful for bodily movement. However, clinical evidence is required [1]. 

Explore Taglus Aligner Sheets 

If you’re looking for an aligner sheet for your lab/clinic, you can find your one stop solution right here. Dentists can look at the full range of sheets, download the catalogue, and speak to the Taglus team. 

References 

1. Elshazly T et al. Clin Oral Investig. 2024. PMID 38637429 DOI: 10.1007/s00784-024-05662-x. 

2. Lombardo L et al. Angle Orthod. 2017;87(1):11-18. PMID 27314603. 

3. Kavya MP et al. APOS Trends Orthod. 2026;16:129-134 DOI: 10.25259/APOS_50_2025. 

4. Cenzato N et al. Appl Sci. 2024;14(15):6533 DOI: 10.3390/app14156533. 

5. Wheeler T, Patel N, McGorray S. J Aligner Orthod. 2017;1(1):21-27. 

6. Medeiros RB et al. Dental Press J Orthod. 2024;29(2):e2423212 DOI: 10.1590/2177-6709.29.2.e2423212.oar. 

7. Ryu JH et al. Korean J Orthod. 2018;48(5):316-325. 

8. Micro-CT study looking at thickness of aligners. Korean J Orthod. 2021;51(2):135-141 DOI: 10.4041/kjod.2021.51.2.135. 

9. Jia L et al. Comput Methods Biomech Biomed Engin. 2022;25(15):1710-1721. PMID 35188858. 

10. Ramasundaram S et al. Systematic review. 2026 DOI: 10.1016/j.ortho.2026.101234.