Crawling
Crawling is when ink or coating pulls away from an area instead of spreading evenly, leaving small bare spots, crater-like gaps, or “islands” in what should be a smooth, solid print. It often looks like the ink “ran away” from certain points on the paper.
Consumers often describe it as:
- “Little holes in the ink”
- “The solid color looks broken or speckled”
- “It looks like the ink separated into islands”
- “Small craters in a solid area”
Crawling is most common in:
- Large solid color areas
- Varnished/coated surfaces
- Areas with contamination (oil, silicone, residue)
Also Known As: Ink crawling, coating crawl, dewetting, beading, fisheyes (sometimes used loosely—see look-alikes), repellency spots, ink rejection.
In simple terms: the ink or coating couldn’t “wet” the surface evenly, so it beaded up and left gaps.
What causes crawling?
Crawling is usually a surface wetting problem. The ink (or coating) needs to spread smoothly across the surface. If the surface has contaminants or has low surface energy, the ink pulls back.
1) Surface contamination (most common cause)
Tiny amounts of contamination can repel ink/coating, such as:
- Oils from handling
- Silicone residue (from sprays, release agents, or packaging materials)
- Waxes
- Lubricants from equipment
- Residue from coatings or cleaning chemicals
Even microscopic contamination can cause many tiny crawl spots.
2) Paper/coating surface energy issues
Some coated or treated surfaces naturally resist wetting:
- Very glossy coatings
- Certain varnishes
- Films/laminates
If the ink/coating system isn't matched to that surface, it may crawl.
3) Incompatible ink/coating combinations
If the chemistry of the ink and the coating/varnish don’t work well together:
- The coating may pull away from the inked areas
- Or the ink may pull away from a treated surface
4) Too much fountain solution / emulsification (offset)
In offset printing, excess water can interfere with ink film stability:
- Ink can lose body
- Film can break
- Crawling becomes more likely in solids
5) Incorrect viscosity / tack / drying conditions
If ink/coating is too thin, too thick, or dries too fast/slow, it can:
- Fail to level
- Break apart into beads
- Leave gaps in coverage
6) Powder/spray interactions
Anti-set-off powders and sprays can create uneven surfaces that cause coatings to crawl or break.
How to identify crawling in a book
What it looks like
- Small round-ish gaps or craters in a solid ink or coated area
- A “cell-like” or “island” pattern where ink coverage breaks up
- Spots where the paper shows through inside a solid color
- Sometimes the edges of the gaps look slightly raised, like ink beaded away
Crawling often has a distinctive pattern:
- Many small voids scattered across a solid
- Not random debris spots—more like a repeated “repelled” effect
Where it shows up most
- Large solid color blocks (covers, backgrounds)
- Smooth coated stocks
- Varnished or coated areas
- Areas likely touched or contaminated (edges, handling zones) or areas affected by spray/powder
Simple at-home checks
Check A: Tilt test
Crawling can show texture differences where ink beaded:
- Under angled light, void edges may catch highlights
Check B: Compare within the same solid
If one solid area is clean but another is cratered:
- It may point to localized contamination or process variability
Check C: Look for repeated “round void” shapes
Debris defects can be random and irregular; crawling often produces more uniform “bead-like” voids.
Common look-alikes (and how to separate them)
1) Hickeys / spots
- Hickeys are often caused by debris and can be larger, more random, sometimes with a halo
- Crawling is a wetting failure and often appears as many smaller, more uniform voids in solids
2) Pinholing
Pinholes can look similar (tiny holes in coating/ink), sometimes used interchangeably in casual descriptions.
For your site, you can treat pinholing as a close synonym/AKA if you want, but crawling specifically emphasizes the ink pulling away.
3) Picking
Picking leaves white specks because paper fibers tear away.
- Picking often feels rough and is paper-surface damage
- Crawling is coverage failure; the paper surface itself may still be intact
4) Mottling
Mottling is blotchy tone variation, not clean “holes.”
Crawling shows distinct voids/gaps.
5) Blistering
Blistering is a heat-related bubble/pit in coated stock (often physical texture).
Crawling is a wetting/repellency issue—more about ink/coating failing to spread, not heat popping.
Impact on book quality and readability
Readability
Usually not a text readability issue unless it affects:
- Fine type printed in solid backgrounds
- Barcodes/QR codes in solid blocks
Appearance
Crawling can be very noticeable:
- Solids look dirty, broken, or cheap
- Photos can look damaged in smooth tone areas
- Covers can look flawed immediately
Durability
Crawling areas can be more vulnerable because coverage is uneven and edges of voids can be weak points for scuffing.
Industry standards and “acceptable tolerances”
Crawling is typically considered a defect when visible because it breaks the intended smooth appearance.
Usually acceptable
- Extremely tiny, rare voids only seen under magnification (uncommon for consumer expectations)
Usually not acceptable
- Obvious crater-like voids in solid areas
- Widespread crawling across large solids
- Crawling on a cover or key graphic areas
- Voids that make a solid look speckled or “holey” at normal viewing distance
A useful rule of thumb: If a solid color looks like it has holes in it without zooming in, it’s likely beyond acceptable variation.
What you can do as a buyer
- Crawling is generally a production defect; a replacement copy often resolves it unless it affected a large portion of the run
- Photograph
- A close-up showing the crater/void pattern
- A wider shot showing how it affects the solid area
Helpful wording for support: "The ink/coating shows crawling (dewetting)—small craters/voids in solid areas where ink pulled away and the paper shows through."