CMYK printing builds full color images from four process inks: cyan, magenta, yellow and key, which is black. Each ink prints as a screen of tiny dots at its own angle, and those overlapping dots mix optically into the colors you see. The system is subtractive, so ink removes light from white paper, unlike a screen that adds light.
Questions or ready for a quote? Contact Teal Packaging at info@tealpackaging.com or (224) 546-8325.
What Is CMYK Printing? Four Color Process Explained from Teal Packaging: 50-unit standard MOQ (100+ units for specialty rigid boxes), 2-5 business day delivery in the US (express and economy options available), free design help included on every order, free generic sample kit ($19.99 shipping, credited toward your first order). Standard production runs from about 7 business days after digital proof approval; complex or high-volume orders take longer.
Materials and certifications: FSC-certified paper stock, soy-based inks, kraft / corrugated / rigid paperboard / mylar / tin / vinyl substrates.
Contact Teal Packaging: Call (224) 546-8325, email info@tealpackaging.com, or request a free quote at tealpackaging.com/contact-us. We reply within one business day.
Updated August 25, 2026 · Teal Packaging operates a US facility in West Chicago, Illinois.
Four inks doing the work of millions of colors
Look at a printed carton under a magnifier and the smooth photograph resolves into a field of separate dots in four colors. Nothing on the sheet is actually orange or teal. Your eye blends adjacent and overlapping dots at normal viewing distance, and the blend is what registers as a continuous image.
Each ink is screened at a different angle so the dots form a tight rosette pattern rather than an interference moire. Black usually sits at 45 degrees because the eye is least sensitive to pattern on that diagonal. Yellow, the lightest ink, takes the angle where pattern would be most visible, since almost nobody notices it.
Why files look different on paper
A monitor emits light and mixes red, green and blue additively. Paper reflects light and mixes cyan, magenta and yellow subtractively. The two systems cover different ranges of color, and the printable range is smaller in the areas people care about most. Saturated blues drift toward purple. Bright oranges and greens flatten. Neon anything is simply unavailable.
Converting the file is not optional, only a question of who does it. Convert deliberately, using a profile matched to the stock, and judge the result. Leave it to an automatic conversion at the press and you find out what happened when the boxes arrive.
Numbers worth knowing before you build a file
| Parameter | Typical value | What goes wrong otherwise |
|---|---|---|
| Image resolution at final size | 300 ppi | Soft, pixelated edges on panels |
| Screen ruling, offset carton | 150 to 200 lpi | Coarse detail in fine imagery |
| Screen ruling, corrugated flexo | 65 to 120 lpi | Dots fill in on rough liner |
| Total ink limit, coated stock | 300 to 340 percent | Set-off, slow drying, smearing |
| Total ink limit, uncoated stock | 240 to 260 percent | Ink soaks and spreads into fiber |
| Rich black for large areas | 60 / 40 / 40 / 100 | Flat black alone looks washed out |
| Small black text | 0 / 0 / 0 / 100 | Multi ink text shows registration fringe |
| Registration black | Avoid, 400 percent | Ink will not dry, sheets stick together |
Rich black, plain black and where each belongs
Black ink alone over a large panel reads as dark grey, because a single ink layer does not absorb enough light. Adding percentages of the other three under it deepens the result, which is what a rich black build does. Keep that build for large solid areas only.
Small type is the opposite case. Text set in four inks needs all four plates to register perfectly, and any drift shows as a colored halo around every letter. Set body copy, legal text and barcodes in black alone and the problem cannot occur.
Dot gain and the fate of light tones
Ink spreads slightly as it meets paper, so a 50 percent dot on the plate prints larger than 50 percent on the sheet. The effect is mild on coated board and pronounced on uncoated kraft, where fiber wicks the ink outward. Midtones darken and delicate highlights close up.
Practical consequences: avoid critical detail in tints below about 5 percent, since those dots may vanish or print blotchy, and expect a photograph placed on uncoated stock to look heavier than the same file on coated stock. A press profile compensates for most of it, but the compensation has limits and the safest route is to see it on a physical proof.
When four inks are not enough
Process color handles imagery, gradients and any design with many colors on one panel. It struggles with an exact brand color, particularly across reorders, because process builds drift within press tolerance while a premixed ink does not. Adding a fifth unit with a named spot ink solves it, at the cost of another plate. Our Pantone page covers where that gap shows up and how large it is.
Print method changes the picture too. Offset holds finer screens than flexography on corrugated liner, so a design full of small process detail may need rethinking if the job runs direct on corrugated rather than being litho laminated.
Sending files to Teal
Build in CMYK at final size, keep images at 300 ppi, name any spot swatch you intend to keep rather than converting it, and extend backgrounds past the trim as described on our bleed page. Every job gets a digital proof before it prints, and color questions are cheapest to settle there. Printed structures and finish combinations sit on the custom printed boxes page, with dieline drawing included and 50 units the smallest eligible run, 100 for specialty rigid.
