Introduction

Open almost any premium product box — a shirt, a serum, a ring, a pair of headphones, a coffee subscription — and there is a small envelope inside. It holds a gift card, a care card, a thank-you note, an instruction sheet, or a warranty card. The box is the product; the envelope is the moment the brand gets to say something after the sale.

These envelopes are a distinct procurement category from mailing envelopes. They are small, made to fit a specific box, printed in short runs, and judged on how they feel in the hand rather than on how they survive a postal stream. And the single decision that shapes everything else — format, print, finishing, and cost — is which paper you make them from.

This guide is built around that decision. It covers what goes into a packaging insert, then gives a comparison of the paper stocks used for it, then the formats and the small-format production problems that follow from the paper choice. For the standard envelope paper context — weights, finishes, and how the paper grades are defined — see our paper types and weight guide; that article covers mailing envelopes, and this one covers the insert envelope that lives inside a box.

EnvelopeDock paper stock warehouse — palletized envelope paper inventory
Paper and board stock for insert envelopes, held in sheets and on pallets. Which weights a plant keeps in stock is the practical limit on the paper options it can offer at short notice.

What Goes Into a Packaging Insert

The insert is usually one of a small set of documents, and each has its own requirements.

InsertWhat It Needs From the Paper
Gift card or voucherRigid, smooth, holds a card without bending
Thank-you cardWarm feel, good writing surface
Care and washing instructionsLegible small print, durability
Instruction or setup cardPrint clarity, sometimes a fold
Warranty or serial cardWriting surface, tamper evidence
Fabric or material swatchTranslucency, or a window
Seed or plant cardCompostability claims
QR code cardSmooth surface, print contrast
Discount or referral cardImpact on a small surface

Industry practice varies by sector, and the sector usually predicts the paper.

SectorTypical InsertPaper Instinct
Apparel and fashionCare card, fabric swatchUncoated or textured, natural
Beauty and cosmeticsThank-you card, samplePearlised or matte coated
JewelleryCertificate, care cardHeavy uncoated or textured
FragranceCard in a small envelopePearlised, foil-stamped
ElectronicsSetup card, warrantyCoated, print-clear
Subscription boxesWelcome card, insert setUncoated, cost-conscious
Food and beverageOrigin card, brewing guideKraft or recycled
Luxury retailCard in a tissue-lined envelopeTextured, heavy, foil

The Comparison: Paper Stocks for Insert Envelopes

This is the core reference. Each row is a stock, and each column is a decision it drives.

StockTypical gsmOpacityPrint FitFoil / Emboss / UVFold-Crack RiskCost
Uncoated card200–300OpaqueOffset, digital, tonerAll three, wellLowLow–mid
Coated gloss (art)150–350OpaqueOffset ideal; toner okFoil and UV excellentHigherMid
Matte coated120–300OpaqueOffset, digitalFoil good; UV subtleHigherMid
Textured / art paper100–250OpaqueOffset; toner variableEmboss excellentMediumMid–high
Pearlised / metallic100–250OpaqueOffset with careFoil and emboss excellentMediumHigh
Kraft / recycled80–200OpaqueOffset, digitalFoil acceptableLowLow
Glassine40–90TranslucentLimited; ink sits on surfaceFoil unreliableLow (thin)Low
Vellum / tracing60–150TranslucentLimited; slow dryingEmboss ok, foil poorLow–mediumMid
Solid bleached board (SBS)200–350OpaqueExcellentAll three excellentMediumMid–high

Read the table as a set of trade-offs rather than a ranking. The cheapest stock is not the worst choice, and the most expensive is not automatically right — what matters is which columns your product actually needs.

If your priority is…Lean toward
Lowest cost at volumeKraft, uncoated
Best print reproductionCoated gloss, SBS
Luxury feelTextured, pearlised
Seeing the card insideGlassine, vellum
Writing on itUncoated
Foil and emboss impactCoated, SBS, pearlised
Sustainability storyKraft, recycled, uncoated
Natural brown kraft paper texture used for packaging insert envelopes
Kraft and recycled boards show visible fibre and a natural shade. They print uncoated and take foil less evenly than coated art paper — the trade-off behind their low cost.

Reading the Columns

Each column deserves a sentence of explanation, because each one is a trap when ignored.

Typical gsm. These are working ranges for insert envelopes, not standards. A small pouch needs enough body to hold its shape and enough flexibility to fold without cracking, which is why the range is narrower than for a mailing envelope.

Opacity. Opaque stocks hide the contents; translucent stocks reveal them. Glassine and vellum are chosen for their translucency, which is why they are in the table at all despite their print limitations.

Print fit. Uncoated and coated both print well, but they print differently: coated stocks hold fine detail and saturated colour, while uncoated absorbs ink and gives a softer, warmer result. Translucent stocks are the constrained case — ink sits on the surface rather than absorbing, which affects drying and detail.

Foil, emboss and UV. Coated and board stocks take foil and emboss cleanly because the surface is smooth and dense. Textured stocks take emboss beautifully and foil inconsistently. Translucent stocks are the opposite: emboss can work, foil often will not.

Fold-crack risk. This is the column buyers discover too late. Coated stocks crack along a fold because the coating is brittle relative to the fibre beneath; heavier weights crack more; a tight fold radius cracks more than a generous one. Uncoated and kraft stocks fold forgivingly.

Cost. A relative band, not a price. It moves with volume, finish, and whether a die already exists.

ColumnThe failure it prevents
gsmA pouch too floppy to hold a card
OpacityContent visible when it should be hidden
Print fitArtwork that looks wrong on the chosen stock
FinishingFoil that will not adhere
Fold-crackCracking discovered after the run
CostA specification the budget cannot carry

gsm to lb: Reading the Same Paper in Two Systems

Most insert specifications arrive in gsm, but some buyers — especially in North America — quote pounds. The two do not convert with a single number, because a pound value depends on the paper grade's basis size.

The practical reference for insert stocks:

gsm≈ lb text≈ lb cover
90~61~33
100~68~37
120~81~44
150~101~55
176~119~65
200~135~74
216~146~80
250~169~92
271~183~100
298~201~110
300~203~111
350~236~129

Read the two lb columns as different papers, not two ways to say the same thing. A "100 lb" insert could be 148 gsm if it is text-grade, or 271 gsm if it is cover-grade — nearly twice the weight from the same instruction.

If a supplier quotes…Ask
"100 lb"Which grade — text, cover, or bond?
"100 lb cover"≈271 gsm — a card-weight stock
"100 lb text"≈148 gsm — a mid-weight sheet
gsm onlyConvert with the grade, not a generic factor

The full conversion method, including why bond, text and cover each use a different basis size, is in our envelope weight conversion guide and in the weight guide linked above. For insert work the rule is simpler: specify gsm, and name the grade if you quote pounds.

The Translucent Options: Glassine and Vellum

These two stocks deserve their own section because they are specified for a different reason than the rest.

Glassine is a thin, dense, translucent paper with a high resistance to grease and air penetration — the property that made it a packaging material historically, and the reason it is still used for food-adjacent and cosmetic inserts. It is smooth, semi-transparent, and folds easily at low weights.

Vellum, in the stationery sense, is a translucent, slightly cloudy sheet used for overlays and envelopes. It is more printable than glassine but still constrained: ink sits on the surface, drying is slower, and heavy coverage can smudge or offset.

PropertyGlassineVellum
AppearanceClear-ish, smoothCloudy, soft
Grease resistanceHighLower
PrintabilityLimitedModerate
FoilUnreliablePoor
EmbossLimitedWorks
Typical useCosmetic, food, soapInvitations, card overlays
If you want…Choose
To see the card clearlyGlassine
A soft, frosted revealVellum
Print on the envelope itselfNeither — use an opaque stock
A window rather than a translucent bagOpaque stock with a die-cut window

Both are worth sampling before committing, because "translucent" covers a wide visual range and the difference between two suppliers' glassine can be obvious in the hand.

Formats for Small Inserts

The format follows both the contents and the box, and the paper choice limits which formats are practical.

FormatConstructionPaper That Suits
Flat card pouchOpen end or side, no gussetUncoated, coated, SBS
Mini walletFolded flap, tuck closureUncoated, textured
Glassine bagFlat, translucentGlassine
Vellum envelopeFlat with a pointed flapVellum
Belly bandWrap around a cardCoated, textured
Window pouchDie-cut windowSBS, coated
String-tie pouchClosure with a tieTextured, kraft
Card + band setCard inside a bandAny
Box contextFormat that works
Flat mailer boxFlat pouch, no bulk
Rigid gift boxMini wallet or vellum envelope
Tube or cylinderSlim band or flat pouch
Drawer boxBelly-banded card
Subscription mailerFlat pouch with a printed card

One practical rule: the insert envelope should be slightly larger than the card it holds but smaller than the void it sits in — large enough that the card does not have to be forced, small enough that it does not rattle around the box.

The Small-Size Problem: Folding, Grain and Cracking

Small envelopes are harder to make than large ones, and the reason is geometry.

ProblemWhy It Happens at Small Size
Fold crackingThe fold radius is small relative to paper thickness
Grain direction faultsA fold across the grain breaks fibres
Die toleranceA fixed tolerance is a larger share of a small dimension
Glue areaLess surface for the same adhesive strength
RegistrationPrint misalignment is more visible on a small face

The grain direction is the one worth understanding, because it is invisible and decisive. Paper has a grain — the direction the fibres predominantly lie — and a fold made along the grain bends between fibres, while a fold made across it breaks them. On a small envelope, where the fold radius is tight, folding across the grain is one of the most reliable ways to produce a cracked, fuzzy fold line.

White uncoated textured card stock for gift card insert envelopes
Uncoated card carries its grain visibly. A fold along the grain bends between fibres; a fold across it breaks them — which is why the same board can fold cleanly on one axis and crack on the other.
PracticeWhy
Plan the die so folds run with the grainAvoids fibre breakage
Score before folding on heavy or coated stockCompresses rather than cracks the coating
Loosen the fold radius where the design allowsReduces stress on the coating
Choose uncoated where the fold is tightMore forgiving fibre structure
Sample the actual foldThe only reliable test

Two consequences follow for the specification. First, the paper and the die are one decision, not two — a die designed for one stock may crack on another. Second, the smallest envelope in a range is the one that sets the paper choice, because it has the tightest fold and the least tolerance.

If your design has…Then
A very tight foldUncoated, lighter weight, scored
A large decorative foldCoated is workable
A die-cut window near a foldExpect cracking; test it
A heavy stock for feelAccept scoring as mandatory

Printing and Finishing on a Small Face

A small envelope gives the printer less room for everything, including error.

TechniqueBehaviour on Small Formats
OffsetExcellent detail; setup suits longer runs
Digital / tonerSuits short runs; check toner adhesion on coated stock
Foil stampingStrong impact; needs clearance from folds
Emboss / debossEffective on textured and board stocks
Spot UVSubtle on small areas; needs a matte base
Die-cut windowAdds a step; check the film or open window
Design constraintPractical limit
Minimum type sizeSmall faces punish fine print
Foil near a foldDistorts at the fold
Emboss near an edgeCan flatten the edge
Heavy ink coverageSlows drying on translucent stock
Full-bleed artRequires accurate die registration

For the finishing side in more depth — what each process does to a surface — see our fancy envelopes guide. That article covers pearlised, metallic and foil-stamped stocks; here the question is narrower, which of those finishes survives a small fold.

Sustainability Claims

Buyers in apparel and beauty often ask for a sustainability story, and this is where claims get sloppy.

ClaimWhat It Actually Requires
RecyclableCheck the local stream and whether coatings or film interfere
FSC-certified paperChain-of-custody certification on the paper itself
CompostableA recognised standard, and the right disposal route
BiodegradableNot the same as compostable; no defined timeframe

On compostability, the distinction matters: ASTM D6400 (US) and EN 13432 (EU) are industrial composting standards, not home-composting ones. They require a high level of biodegradation within a defined period and low residue, and they apply to the material — not to the envelope as a marketing adjective.

Say thisNot this
"Paper from certified sources""Eco-friendly"
"Certified industrially compostable to ASTM D6400""Compostable" without a standard
"Recyclable in kerbside paper streams""Fully recyclable" without qualification
"Plastic-free window""Sustainable"

Two practical cautions. A window film, a coating, or a foil can make an otherwise paper envelope non-recyclable in a given stream, so the claim has to be about the finished item, not the base paper. And a compostability claim that depends on an industrial facility is misleading if the customer will put it in a home bin.

Ordering: Dies, Minimums and Sampling

Small envelopes are die-cut, so the ordering conversation is about tooling as much as paper.

DecisionWhat It Affects
Die exists for the size?Whether a one-time tooling charge applies
Paper stockFold behaviour, print result, cost
Print methodShort runs favour digital
FinishingAdds passes and registration risk
Quantity per SKUSmall sizes still carry setup
Number of SKUsA set of inserts usually means several
For a first orderDo
Ask whether a stock die fitsAvoids unnecessary tooling
Request a white sample firstTests the fold and the format
Then a printed sampleTests colour and finish
Test with the real cardConfirms fit, not just dimensions
Confirm the carton countThese are small and light; freight is volumetric

The sample-approval sequence is the same as for any custom envelope; what changes here is that you must fold the sample and load the real card. For this product, add two checks: fold the sample along the intended line, and put the actual card inside it.

Common Mistakes

MistakeConsequenceFix
Choosing paper before the fold is designedCracking discovered at productionDecide paper and die together
Coated heavy stock with a tight foldCracked fold lineScore, or move to uncoated
Folding across the grainFuzzy, broken foldPlan the die with the grain
Translucent stock for printed artworkPoor ink resultUse opaque stock, window if needed
Foil across a foldDistorted foilKeep foil clear of folds
"Compostable" with no standardUnsupported claimName the standard, and the route
Sizing to the card onlyPouch will not sit in the boxSize to card plus box void
Skipping the white sampleFold problem found lateWhite sample first

Conclusion

Packaging insert envelopes are a paper decision before a format decision. Uncoated and kraft stocks fold forgivingly and feel warm; coated stocks print beautifully and crack more readily; textured and pearlised stocks carry the luxury signal; SBS gives the best of both at a higher cost; and glassine and vellum are chosen for translucency, accepting their print limits.

The two rules that cause the most rework are both about the fold: plan the die so folds run with the grain, and score heavy or coated stock rather than folding it flat. Then match the format to the box void, keep foil clear of folds, and be precise about sustainability claims — name the standard, and name the disposal route.

For the paper definitions themselves, see our paper types and weight guide; for gift-giving contexts rather than packaging inserts, our gift envelope packaging guide; for card-and-envelope sets, our custom note cards and envelopes article.

Specifying an insert for a product box? Request a quote with the card size, the box void, and the paper you are considering.