What is grain direction?
Paper has fibres that line up in one direction during manufacturing. That direction is called the grain. The grain runs either:
Long grain — parallel to the longer side of the sheet, or
Short grain — parallel to the shorter side of the sheet.
Grain direction matters in commercial print because:
Bound books want the grain running parallel to the spine. Grain across the spine causes the pages to fight the binding, the book won't lie flat, and pages can crack along the spine over time.
Folded products (brochures, leaflets, folders) fold cleanly when the fold runs with the grain. A fold across the grain produces a rough, cracked fold edge.
Flat products (flyers, posters, business cards, postcards) are not sensitive to grain.
When a job has a grain requirement, the prepress operator may not be free to rotate pages on the press sheet however they like. Removing that rotation freedom can mean fewer pages fit on each sheet, which means more sheets are printed, which means a higher paper cost. That's why grain direction can change your estimate.
How Gelato uses grain direction
Gelato treats grain as deterministic — there is no per-job dropdown asking the user "which direction should the grain run?" Instead, the rules are well known by the industry, and the system applies them automatically:
For bound books, grain runs parallel to the spine.
For folded products, grain runs parallel to the primary fold.
For everything else, grain has no effect.
You enable this behaviour per substrate (so the paper "knows" its grain) and per product category (so the category "knows" whether to enforce the rule). Once that is set up, every estimate using that paper and that category will respect the rule with no extra clicks.
Setting it up
There are two places you configure grain direction.
1. On the substrate (paper)
For each commercial print substrate, you can set the grain direction:
Setting | Meaning |
Long | Grain runs along the longer dimension of the sheet |
Short | Grain runs along the shorter dimension of the sheet |
(blank) | Grain not specified — the substrate behaves as it always has |
Tip: Many paper merchants mark grain by underlining the grain dimension on the catalogue (e.g. 700×1000) or with the abbreviations LG (long grain) and SG (short grain).
This setting is only available on commercial print substrates. Large format substrates do not use grain direction.
2. On the product category
Each category has two grain controls:
Control | What it does |
Enforce grain direction | When ON, the system automatically applies the grain rule for any estimate in this category. When OFF, grain is ignored even if it is set on the paper. |
Allow override per estimate | Only relevant when enforcement is ON. When ON, the user creating an estimate can choose to disable the grain rule for that one estimate. When OFF, the rule is always applied with no opt-out. |
Both controls default to OFF. If you do nothing, grain has zero impact and your estimates will behave exactly as they always have.
Recommended defaults
Category type | Enforce | Allow override |
Perfect-bound books, saddle-stitched books, case-bound books | ON | OFF |
Brochures, folders, leaflets | ON | ON |
Flyers, posters, business cards, postcards | OFF | OFF |
Wire-O, spiral, twin-loop bound books | OFF | OFF |
When does grain actually affect the layout?
This is the most important section, because it is the one most printers ask about. Grain only constrains the layout when all of the following are true:
The paper has a grain direction set (Long or Short).
The category has Enforce grain direction turned ON.
The user has not disabled grain on the estimate (only possible when override is allowed).
The product type is one the rule applies to (see below).
If any one of these is missing, the layout is calculated exactly as it always has been.
Products that ARE affected
Saddle-stitched books — the sheet is folded into a signature; grain must run parallel to the spine.
Perfect-bound (PUR) books with signatures — same reason.
Case-bound (hardcover) books — same reason.
Folded brochures, leaflets, folders, menus — grain must run with the primary fold.
Products that are NEVER affected
Even when grain is enabled and set, these products are deliberately excluded from the rule because they have no signature folding and no spine fold:
Wire-O, spiral, and twin-loop bound books. Each page is printed and trimmed individually and then bound with a coil — there is no signature, so the spine-fold quality concern does not exist. Grain alignment along the spine is a "nice to have" rather than a structural requirement, and Gelato does not constrain it.
All flat products — flyers, posters, postcards, business cards, sell sheets. There is no fold, no spine, and no folding-quality concern.
Why this matters in practice: A printer who sets a grain direction on their stock and turns on enforcement at the category level for "Wire-O notebooks" will see no change in their estimates. The system is doing what is correct — Wire-O does not need a grain constraint — and is not double-counting paper because of a setting that does not apply.
Step folds, stitching, and "is the spine fold counted?"
A common question: "When a saddle-stitched book is folded and stitched in the same step, is the grain rule applied to the fold or the stitching?"
The answer is simpler than it sounds. Gelato looks at the primary fold of the printed sheet, not at the finishing equipment used. If the press sheet is folded into a signature — whether that fold happens in a separate folding pass or as part of a combined fold-and-stitch step — the grain rule is applied. The stitching itself is a finishing operation and does not on its own trigger a grain constraint.
In other words:
Saddle-stitched book → press sheet is folded into a signature → grain rule applies, regardless of whether folding and stitching happen in one machine pass or two.
Wire-O book → individual pages are printed and trimmed, then bound with a coil → no press-sheet fold → grain rule does not apply.
The rule is "does the press sheet get folded into a signature?", not "is the product bound?".
Cross-folds (French fold, map fold, multi-panel folds)
Some products have more than one fold direction (for example, a French fold has a horizontal fold and a vertical fold). Paper can only have one grain direction, so grain can only line up with one of the folds.
Gelato follows the industry standard: grain runs parallel to the primary fold. The secondary fold is treated as a finishing detail (where a score or crease is the right answer), and it does not add a second grain constraint to the layout.
If your job has multiple folds, you can think of grain as being aligned with the longest or most structurally important fold.
How grain shows up in the imposition viewer
When grain enforcement is active for a job, the imposition viewer shows the grain direction so you can verify it visually before approving the layout. You will see an indicator on the press sheet (typically a dashed arrow or fibre lines) showing which way the fibres run relative to the layout.
For a bound book, you should see the arrow pointing along the height of the finished page, parallel to the spine. For a folded brochure, you should see the arrow running along the primary fold.
If the category has grain enforcement turned on but the product is one of the excluded types (Wire-O, flat product, etc.), the indicator may still be displayed for reference, but the layout will not have been constrained by it.
Effect on price
Grain enforcement can change the price of a job — almost always upward, never downward. The mechanism is straightforward:
Without a grain constraint, the system tries every page rotation on the sheet and picks the one that fits the most pages.
With a grain constraint, one rotation is no longer allowed because it would put the grain in the wrong direction.
The remaining (allowed) rotation may fit fewer pages per sheet.
Fewer pages per sheet means more sheets are needed, which means more paper cost.
There is no separate "grain charge" or extra line item. The cost difference flows naturally through the existing paper cost on the estimate. If you compare the same job with grain enforcement on and off, you will see the difference in the paper line of the cost breakdown.
Per-estimate override
When a category has both Enforce grain direction and Allow override per estimate turned on, the user creating an estimate has an extra option (under "Show more" in the create-estimate form, and per-part in the imposition viewer) to disable grain for that single estimate.
This is intended for genuine edge cases — for example, a customer who has explicitly accepted that their book will be printed against the grain to keep the price down. Use it sparingly. It does not change the configuration; it only affects that one estimate.
If override is not allowed, the user has no opt-out and the rule is always applied.
Migrating away from the duplicate-paper workaround
Before grain direction was supported, some printers worked around it by creating two paper records for the same stock — one in each orientation (e.g. a 450×320 sheet and a 320×450 sheet). This is no longer needed.
We recommend:
Keep a single paper record for each stock.
Set its grain direction (Long or Short) on the substrate.
Turn on grain enforcement on the categories where it matters (books and folded products).
Delete the duplicate orientation entries once nothing references them.
This keeps your configuration clean and makes the grain semantics explicit rather than hidden inside a duplicate paper name.
Quick reference
Situation | Will grain change my estimate? |
Paper has no grain set | No |
Category has enforcement OFF | No |
Flat product (flyer, poster, business card) | No |
Spiral binding | No |
User toggled the per-estimate override | No |
Saddle-stitched, perfect-bound, or case-bound book with grain set and enforcement ON | Yes — grain runs parallel to the spine |
Folded brochure / leaflet / folder with grain set and enforcement ON | Yes — grain runs parallel to the primary fold |
Frequently asked questions
Will turning grain enforcement ON for an existing category break my prices?
Only on jobs where grain enforcement actually applies (bound books and folded products on a substrate that has grain set). Wire-O, flat products, and any paper without a grain direction will be completely unaffected.
Can I set grain direction on a substrate without enforcing it anywhere?
Yes. The grain field on the substrate is informational on its own — nothing happens until a category turns enforcement on. This is useful if you want to record the grain direction in your catalogue but are not yet ready to apply it to estimates.
Can the user pick the grain direction when creating an estimate?
No. Grain direction is a property of the paper, not a per-job choice. The user picks the paper; the paper carries the grain. The only per-estimate control is the override toggle (when allowed), which disables the constraint for that one job.
What about large format printing?
Grain direction does not apply to large format substrates. The setting is only available on commercial print papers.
Where do I see whether grain affected a particular estimate?
Open the imposition viewer for the estimate. If grain is active you will see the grain indicator on the press sheet. Compare the paper line in the cost breakdown against the same job with override enabled to see the cost impact.