TLDR
- A typical non-foil Magic card is close to 0.305 mm thick, or about 305 microns and 12 points.
- For a familiar standalone card feel, target roughly 0.30 to 0.32 mm finished thickness.
- GSM measures weight per area, not physical thickness. Two 330 GSM stocks can have different calipers.
- Black-core playing card stock around 300 to 330 GSM is usually the strongest starting point for professionally printed proxies and custom TCG cards.
- Opaque sleeves hide card backs and make small differences in finish less noticeable, but they do not remove differences in deck height or stiffness.
- For home printing, a thin paper insert placed over a basic land inside an opaque sleeve is often easier than forcing heavy card stock through a consumer printer.
Two sheets of card stock can both be labelled 330 GSM and still feel noticeably different. One may be dense, thin, and snappy. The other may be thicker, softer, and reluctant to shuffle.
That is why MTG proxy card thickness should not be chosen from GSM alone. The finished card’s caliper, core, coating, stiffness, grain, surface finish, and cut quality all affect how it handles. And once cards are placed into a 60-card or 100-card deck, even a small difference becomes easier to notice.
For most non-foil proxies and custom trading cards, a finished thickness close to 0.30 to 0.32 mm is the practical target. That equals about 300 to 320 microns, or roughly 12 to 12.6 points.
The Direct MTG Proxy Card Thickness Recommendation
A typical non-foil Magic card is commonly measured at about:
- 0.012 inch
- 0.305 millimetres
- 305 microns
- 12 points
Production varies slightly between print runs, card treatments, moisture conditions, and manufacturing locations. The goal is not to make every proxy exactly 0.305 mm to the final micron. The goal is to choose a finished construction that behaves naturally in the intended deck.
| Finished Thickness | Points | General Use |
|---|---|---|
| Below 0.25 mm | Below 10 pt | Paper inserts and temporary prototypes |
| 0.25–0.285 mm | 10–11.2 pt | Lightweight sleeved cards |
| 0.29–0.32 mm | 11.4–12.6 pt | Strong target for MTG-style cards |
| 0.325–0.36 mm | 12.8–14.2 pt | Heavy custom cards and stiff decks |
| Above 0.36 mm | Above 14.2 pt | Usually too bulky for an MTG-style mixed deck |
A slightly thin proxy may work perfectly in opaque sleeves. A slightly thick proxy may also feel acceptable when the complete deck uses the same stock.
Mixing cards is less forgiving. If proxies are shuffled together with authentic cards, differences in thickness, stiffness, corners, backs, or finish can make cards identifiable.
How Points and Microns Convert
Points measure physical thickness.
1 point = 0.001 inch
Since one inch equals 25.4 millimetres:
1 point = 0.0254 mm = 25.4 microns
That gives the following useful conversions:
| Points | Inches | Millimetres | Microns |
|---|---|---|---|
| 10 pt | 0.010 in | 0.254 mm | 254 μm |
| 11 pt | 0.011 in | 0.279 mm | 279 μm |
| 12 pt | 0.012 in | 0.305 mm | 305 μm |
| 13 pt | 0.013 in | 0.330 mm | 330 μm |
| 14 pt | 0.014 in | 0.356 mm | 356 μm |
Microns and points can be converted because both measure thickness. GSM cannot be converted as reliably because it measures something different.
Why GSM Is Not Card Thickness
GSM means grams per square metre. It tells you how much one square metre of material weighs.
It does not directly tell you how thick the material is.
A dense, compressed 330 GSM sheet may be thinner than a softer 300 GSM sheet. Coatings, fibres, core material, moisture, compression, and manufacturing methods all change the relationship between weight and thickness.
This is why online GSM conversion charts should be treated as estimates. They can be useful when comparing papers from the same manufacturer and product family. They are much less reliable when comparing unrelated stocks.
When ordering custom TCG cards, ask for both:
- GSM or paper weight
- Finished caliper in microns or millimetres
A physical sample is better than either number. It lets you test shuffling, bending, opacity, print quality, sleeves, and deck height before committing to a larger order.
Is 300 or 330 GSM Better for MTG Proxies?
Both can work.
For professional card production, black-core stock in the general range of 300 to 330 GSM is common. The better choice depends on the stock’s actual caliper and construction.
A dense 300 or 310 GSM black-core stock may feel closer to a standard trading card than a bulky 330 GSM white-core stock. The 330 GSM label does not automatically mean the card will feel more authentic.
Use this order of importance:
- Finished thickness
- Core and opacity
- Stiffness and snap
- Surface finish
- Cut and corner quality
- GSM
GSM still matters. It is simply not enough by itself.
Why Black-Core Card Stock Is Usually Preferred
Black-core card stock contains a dark internal layer between the printed faces.
That core serves several purposes:
- It blocks light passing through the card.
- It helps prevent the front image from showing through the back.
- It creates a more familiar playing-card snap.
- It provides stiffness without requiring excessive thickness.
- It reduces the risk of players identifying cards from light transmission.
Blue-core and grey-core materials can also offer useful opacity. White-core card stock is often easier to source, but it may allow more light through and can feel different at the same nominal GSM.
The word “black core” does not guarantee quality. Stock can still be too thick, too soft, badly coated, or poorly cut. Ask for samples and finished caliper data.
Thickness Is Only One Part of Card Feel
Players sometimes match the thickness closely and still find that the proxy feels wrong.
That usually happens because card handling depends on several properties at once.
Stiffness
A card can be thin but stiff or thick but soft. Fibre direction, core construction, adhesives, and coatings all affect bending resistance.
Snap
Snap is the card’s tendency to spring back after being flexed. Layered playing card stock normally has a different response from a single sheet of ordinary cover paper.
Surface Finish
Gloss, matte coating, varnish, linen texture, and lamination affect friction. A rough card may resist mash shuffling. A slick card may slide too easily.
Corners
Poorly rounded corners catch on sleeves and neighbouring cards. Even a correct card thickness can feel unfinished when the corner radius is inconsistent.
Cut Accuracy
Cards with slightly different widths or heights can become identifiable during handling. Accurate cutting matters as much as caliper when cards will share one deck.
How Sleeves Change the Result
Opaque sleeves solve several problems.
They hide differences between card backs, reduce visible wear, protect printed surfaces, and make minor finish variations less obvious. They are especially useful for double-sided cards and paper inserts.
But sleeves do not make every construction identical.
A thickness difference of only 0.02 mm becomes 2 mm across a 100-card deck before the sleeve material is counted. That can change deck-box fit and the height of the stack.
Stiffness differences can also remain noticeable during shuffling. A thin insert over a basic land may feel natural because the authentic card supplies the structure. A thick proxy in the same deck may resist bending more than the surrounding cards.
For casual Commander decks in opaque sleeves, small differences are usually easier to tolerate. For unsleeved cards or mixed tournament-style decks, manufacturing differences are much more visible.
Recommended Thickness by Use Case
| Use Case | Recommended Approach |
|---|---|
| Temporary deck testing | Thin paper insert over a basic land in an opaque sleeve |
| Casual sleeved Commander deck | Approximately 0.28–0.32 mm finished thickness |
| Standalone custom TCG deck | Approximately 0.30–0.34 mm, depending on desired stiffness |
| Mixed deck with authentic cards | Stay close to 0.30–0.32 mm and test carefully |
| Unsleeved custom cards | Use opaque playing card stock with a durable finish |
| Display cards or tokens | Thickness can vary more because cards are not hidden in a library |
The correct answer depends partly on whether every card uses the same material. A complete custom deck can be slightly heavier or lighter while still feeling consistent. A few replacement cards inside an existing deck need a closer match.
How Card Thickness Affects Shuffling
Cards that are too thin may:
- Bend easily
- Develop creases
- Clump together
- Feel flimsy during overhand shuffling
- Slide underneath thicker cards
- Produce a shorter deck stack
Cards that are too thick may:
- Create an unusually tall deck
- Fit poorly in deck boxes
- Resist mash shuffling
- Place extra pressure on sleeves
- Feel rigid rather than snappy
- Make large Commander decks harder to hold
Surface friction also matters. Thick cards with a smooth finish may shuffle more easily than thinner cards with a tacky coating.
Test a complete deck, not just one card. A sample that feels acceptable by itself may become tiring to shuffle when repeated 100 times.
Double-Sided Cards Need a Different Plan
Printing on both sides of one suitable sheet does not automatically make a card thicker. The thickness remains the thickness of the original stock plus its coatings.
Problems arise when two complete printed sheets are glued together. Two 0.20 mm sheets plus adhesive could create a card well above 0.40 mm. That is much thicker than a normal trading card.
For double-sided custom cards:
- Print both sides directly when the stock and printer support accurate duplex registration.
- Use opaque sleeves when the back face would otherwise reveal the card.
- Keep front and back templates aligned.
- Test the direction in which the back image rotates.
- Include registration tolerance around borders.
- Avoid joining two heavyweight sheets.
For transforming Magic cards, an opaque sleeve prevents the reverse face from identifying the card while it is in a hidden zone. A separate helper card or checklist system may also be easier during testing.
Home Printing Changes the Recommendation
Many consumer printers are not designed for 300 to 330 GSM playing card stock. Some cannot feed it. Others can feed it only through a rear or manual slot. Automatic duplexing may also be unavailable for heavy media.
Check the printer’s supported media weight and thickness rather than assuming “card stock” is acceptable.
There are four practical home-printing methods.
Paper Insert Over a Basic Land
Print on ordinary or slightly heavier paper, cut out the image, and place it over a basic land inside an opaque sleeve.
This is inexpensive, easy to revise, and close to the correct final stiffness because the real card acts as the structural layer.
Lightweight Standalone Card Stock
Card stock around 180 to 250 GSM is easier for many printers to feed. It can work for classroom games, prototypes, tokens, or fully sleeved test decks.
It will normally feel lighter than a commercial TCG card.
Specialty Black-Core Sheets
Some black-core card stocks are sold in printer-sized sheets. Check whether the material is compatible with inkjet, laser, toner, or another print method.
Heavy stock may require manual feeding, one sheet at a time, and a specific media setting. Print adhesion can also vary with the coating.
Professional Printing
Outsourcing is the most predictable option when you need accurate front-to-back alignment, black-core stock, consistent cutting, rounded corners, and repeated deck production.
Order a small proof before approving a large run.
Be Careful With Lamination
Lamination adds thickness, stiffness, and surface friction.
A laminated 200 GSM sheet may end up thicker than an unlaminated 300 GSM playing card stock. Adhesive layers and protective films count toward the finished caliper.
Lamination can be useful for:
- Frequently handled classroom cards
- Tokens
- Reference cards
- Outdoor or moisture-resistant game pieces
It is less useful when the goal is to closely imitate standard MTG card handling. Heavy pouch laminate can make cards feel plastic, rigid, and bulky.
When comparing specifications, measure the complete finished card after printing, coating, mounting, and lamination.
How to Measure a Proxy Card
A digital caliper is the simplest tool, but measuring one flexible card can produce inconsistent readings.
Use this method:
- Choose ten finished cards.
- Stack them neatly.
- Measure the stack away from raised edges or debris.
- Divide the measurement by ten.
- Repeat in two or three locations.
- Record the average.
For example, a ten-card stack measuring 3.08 mm has an average card thickness of:
3.08 ÷ 10 = 0.308 mm
Measure authentic reference cards using the same method and tool. The comparison is often more useful than relying on a number published for a different card set or production run.
Do not squeeze the caliper hard enough to compress the stack.
Create a Complete Card Stock Specification
When requesting a quote, do not ask only for “330 GSM cards.”
Use a specification such as:
- Finished size: 63 × 88 mm or 2.5 × 3.5 inches
- Finished caliper target: 0.30–0.32 mm
- Stock: black-core playing card stock
- Weight: approximately 300–330 GSM
- Printing: full colour on both sides
- Finish: matte varnish, smooth coating, or requested texture
- Corners: rounded consistently
- Packaging: sorted decks or bulk cards
- Proof: physical sample or short proof run
- Intended use: sleeved custom TCG deck
The printer may recommend a specific house stock. Ask for the stock’s measured caliper and a sample rather than rejecting it because its GSM differs slightly from an online recommendation.
A Note About MTG Proxies and Sanctioned Play
Card thickness does not determine tournament legality.
Wizards distinguishes casual playtest cards from judge-issued tournament proxies. In sanctioned Magic events, players generally need authentic authorised cards. A judge may issue a temporary proxy in limited circumstances, such as when a card is damaged during the event.
Casual groups, unsanctioned events, and local stores may establish their own playtest-card policies. Check with the organiser before arriving with a proxy deck.
Custom cards should also be clearly presented as unofficial. They should not be designed or marketed in a way intended to deceive someone into believing they are authentic Magic cards.
Final Recommendation
For professionally printed MTG proxies or custom TCG cards, begin with a finished thickness of approximately 0.30 to 0.32 mm, equivalent to 300 to 320 microns or about 12 to 12.6 points.
Black-core playing card stock around 300 to 330 GSM is a strong material category, but confirm the actual caliper. Do not select stock from GSM alone.
For home playtesting, use a printed insert over a basic land in an opaque sleeve unless your printer is specifically designed to handle heavy specialty card stock.
And always test a complete deck. The correct card is not merely the one that matches a number. It is the one that prints cleanly, remains opaque, fits the sleeves, shuffles consistently, and does not stand out from the cards around it.
FAQs
Is 300 GSM Thick Enough for MTG Proxies?
It can be. A dense 300 GSM black-core stock may have an appropriate thickness and stiffness. Ask for its finished caliper rather than judging it from GSM alone.
Is 330 GSM the Same as 0.33 mm?
No. GSM measures weight per square metre. Millimetres measure thickness. A 330 GSM stock may be thinner or thicker than 0.33 mm.
How Many Microns Thick Is a Magic Card?
A typical non-foil card is commonly measured at approximately 305 microns, although production variation exists.
Are Thicker Proxy Cards More Durable?
Not automatically. Core construction, coatings, fibre direction, finish, and flexibility all affect durability. An overly thick card may be rigid and difficult to shuffle.
What Is the Easiest Home Method?
Print a thin insert, cut it to size, and place it over a basic land inside an opaque sleeve. This avoids forcing heavy card stock through an unsupported printer.
Should Custom TCG Cards Use Black-Core Stock?
Black-core stock is a strong choice when opacity, snap, and a traditional playing-card feel matter. It is not required for prototypes, tokens, or inexpensive classroom decks.
References
- PrintMTG, “Understanding PT, GSM, and LB for MTG Proxy Printing,” for the distinction between thickness measurements and paper weight, along with the approximate 12-point target.
- PrintMTG, “What Card Stock Does Magic: The Gathering Use?” for commonly cited Magic card dimensions, thickness, and card-stock weight ranges.
- Draftsim, “MTG Card Size, Dimensions, Weight, and More,” for the commonly measured non-foil thickness of approximately 0.012 inch or 0.305 mm.
- PrintNinja, “Black Core Cardstock,” for the use of 310 and 330 GSM black-core materials in professional playing-card production.
- VistaPrint, “Complete Guide to Paper Thickness and Weight,” for point and caliper terminology, including one point equalling one-thousandth of an inch.
- Epson Support, “Printing on Card Stock or Matte Board,” for an example of printer-specific thickness limits and manual rear feeding requirements.
- Wizards of the Coast, “On Proxies, Policy, and Communication,” for the distinction between casual playtest cards and authentic cards required in sanctioned events.
- Wizards Play Network Policy Hub, for the current WPN category covering proxy use and counterfeit cards.