MDF Movement Trays: Measuring Your Bases Before You Buy

Quick answer

Measure your miniature bases with digital calipers, not a ruler. Confirm the base footprint in millimeters, count the exact number of models you want per tray, and match those numbers to the tray's column-by-rank layout. If you are unsure, order a single tray first to test the fit before committing to a full set.

Why base measurement matters more than base labels

Base labels like '25mm' or '20mm' are nominal, not exact. Manufacturing tolerances, resin shrinkage, and the thickness of paint and texture paste can add up to a millimeter or more. A tray cut for 20x20mm bases may not accept a base that actually measures 20.8mm after basing. Measuring the physical base—not trusting the label—prevents the frustration of a tray that will not close or a loose fit that lets models slide.

How to measure a base accurately

Use digital calipers for the most reliable reading. Measure across the widest point of the base's footprint, from edge to edge. If you are using round bases, measure the diameter. For square or rectangular bases, measure both width and depth. Take three measurements per base and average them. If you plan to add texture paste or thick paint later, add 0.5–1mm to your measurement to account for that buildup.

Count your models and plan your tray layout

Trays are listed as Columns (width) x Ranks (depth). Decide how many models you want in a single tray. A 12x5 tray holds 60 models in 12 columns and 5 ranks. A 10x3 skirmish tray holds 30 models. The layout affects how the unit moves on the tabletop: wider frontage gives more attack width, deeper ranks make the unit more compact. Match the tray layout to how you actually play the unit, not just to the number of models you own.

Check tray spacing and trim

Some trays include built-in spacing between cutouts. For example, a skirmish tray may place each cutout 1/2 inch apart with a 1/4 inch trim to maintain consistent spacing between individual bases. This matters for skirmish games where models need room to rotate or where base-to-base contact is not required. If your game requires tight base-to-base contact, you need a tray with minimal spacing. Always read the tray description for spacing details—if the spacing is not listed, ask the seller before ordering.

Decide if you need a conversion tray

Conversion trays let you use smaller bases while matching the frontage and depth of larger bases. For example, a 30x30mm conversion tray for 25x25mm bases centers 25mm figures so they occupy the same footprint as 30mm figures. This is useful when a new edition changes base sizes or when you want to keep your existing miniatures compatible with updated rules. Measure both the actual base size and the target base size before choosing a conversion tray.

Select frame height and base options

Frame height determines how much of the base sits inside the tray. A taller frame holds models more securely but may hide more of the base edge. A shorter frame is lighter and easier to handle but offers less protection. Some trays also offer a base option—this means the tray includes a lower base piece that the miniatures stand on, rather than just an upper frame. If you already have based miniatures, you likely only need the frame. If you are starting from scratch, a tray with a base gives you a complete movement solution. Check the available options for each product before adding to cart.

Step-by-step: measuring and ordering your tray

1. Measure your base footprint: Use digital calipers to measure the width and depth (or diameter) of a based miniature. Average three readings. Add 0.5–1mm if you plan to add texture or thick paint later. Checkpoint: Write down the exact millimeter measurement, not the nominal base size.
2. Count the models per tray: Decide how many miniatures you want in one tray. This determines the number of cutouts you need and the tray's overall footprint. Checkpoint: Confirm the tray's column x rank layout matches your desired unit formation.
3. Check spacing and trim: Read the tray description for cutout spacing. Some trays have extra spacing for skirmish games; others are tight for ranked units. Checkpoint: If spacing is not listed, contact the seller before ordering.
4. Choose frame height and base option: Select a frame height that matches your basing style and storage needs. Decide if you need a tray with a lower base or just an upper frame. Checkpoint: Taller frames hold models more securely but add bulk; shorter frames are lighter but offer less protection.
5. Order one tray as a test: If you are unsure about the fit, buy a single tray first. Test it with your actual miniatures before ordering multiple trays. Checkpoint: A loose fit means models slide; a tight fit means you may damage paint. Adjust your measurements if needed.

Example trays and what to check

• 11 x 7 Movement Tray for 20 x 20mm Bases: This 11 x 7 movement tray is designed for 20 x 20mm bases and consists of an MDF upper frame and lower base. The base's border and upper frame measure 1/4 inch (6.35mm) per side. You can select the frame height and base option. If your 20mm bases are actually 20.5mm or larger, they may not fit. Measure first and add a little clearance for paint.
• 10 x 3 Skirmish Tray for 50 x 50mm Bases: This 10 x 3 skirmish tray is for 50 x 50mm bases. Each cutout is placed 1/2 inch (12.7mm) apart with a 1/4 inch (6.35mm) trim to maintain consistent spacing between individual bases. You select the frame height to match the depth of your miniatures' bases. The built-in spacing means models will not touch base-to-base. If your game requires contact, this tray may not be suitable.
• 12 x 5 30x30mm Conversion Tray for 25x25mm bases: This 12 x 5 conversion tray allows 25x25mm based figures to be centered and have a frontage and depth of 30x30mm based figures. Trays are listed as Columns (width) x Ranks (depth). You select the frame height and base option. Useful if you are rebasing or adapting older miniatures to a new edition with different base sizes. Measure both the actual base and the target footprint.