Shrink Sleeve Specifications by MikeJenny


									                        SHRINK SLEEVE FORMULAS
Determining Label Size
  1. Measure largest circumference of container / 2 = Exact size of sleeve. Now add
     3mm to this measurement to determine Layflat Size.
     Circumference of 180mm / 2 = 90mm + 3mm = 93mm Layflat Size
     (Label Layflat size for automatic application should ALWAYS be sized by automatic
     application machine manufacturer)
  2. Layflat Size x 2 + 1mm = Print Width  This 1mm is for ink overlap at seam.
     Layflat of 93mm x 2 = 186mm + 1mm = 187mm Print Width
  3. Layflat size x 2 + 7mm = Slit Width
     Layflat of 93mm x 2 = 186mm + 7mm = 193mm Slit Width
     (7mm is calculated as – 5mm clear glue area, 1mm print overlap & 1mm clear on edge
     opposite glue edge)          Note: leave 2mm clear at slit edges before starting any
  4. Cut Length for sleeve will be determined by customer requirements for style of
     sleeve whether partial sleeve, full sleeve or full sleeve with tamper evident
     protection. Once style of sleeve is determined then carefully measure container
     over all contours taking care to identify longest surface length on container. To
     this measurement then add MD material shrinkage plus press snap back. Now
     review you plate cylinder chart and determine what size cylinder will be the best
     fit. This final size will determine the repeat length for sleeve Cut Length.
     Measured height of container is 200mm and the material you choose has a 2%
     MD shrinkage plus a press snap back of .0625”
     Length of 200mm + 2% MD shrink = 204mm + press snapback of 1.5mm =
     205.5mm. Closest cylinder selection is 8.125” which equals to 206.375mm. The
     difference in size being + .875mm.
  5. Print Height now can be determined by subtracting 4mm from the repeat length.
     A repeat of 206.375mm – 4mm = 202.375mm Print Height.
     (This will allow for a 2mm clear area at top and bottom of finished label)
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Material Shrink Percentage
      To determine the amount of shrink in a film required for a specific container it
      will be necessary to measure the circumference of the container at its largest point
      and smallest point. Then divide the largest number into the smallest number and
      subtract that number from one. The final number will determine the shrink
      70mm smallest circumference / 180mm largest circumference = .38
      1.0 - .38 = 62% shrink

Seam Location
      Seam location will very from one shrink sleeve to another depending on a variety
      of different variables which may include container shape and style, automatic or
      hand application of label and design of artwork.

Pre-Distortion of Artwork
      Pre-distortation of artwork for a shrink sleeve is typically performed in high
      shrink areas of container. If in the opinion of the converter a label warrants pre-
      distortion of artwork, it is his responsibility to contact the customer with the
      recommendation. It is always the customer’s final decision whether to ok and pay
      the additional cost to pre-distort artwork.

Manual Pre-Distortion of Artwork
      Create a black grid pattern .25” x .25” with a line width of .020”. This pattern
      should be printed on the same substrate that the finished label will be
      manufactured on. Once grid is printed make a hand sample to finished label size
      and send to customer for shrinking. One important factor is the customer must
      shrink this sample on the container utilizing the same shrink tunnel that will be
      used to manufacture the order. Sample container should then be sent back to
      converter to determine art distortion criteria. At converter the label can be cut off
      of container and the grid measured in high shrink areas to determine amount of
      shrink that occurred in those areas. A percentage difference can then be calculated
      and artwork distorted to compensate for shrinkage.
      Original grid of .25” once shrunk is now .125” then artwork should be sized 50%
      larger in that specific area. The mathematical calculation of the shrink factor is
      always a percentage of original grid size.

Electronic Pre-Distortion of Artwork
      There are numerous software packages that can supply an electronic method to
      pre-distort artwork. They utilize a computerized version of the manual grid

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Color Change in High Shrink Areas
     Caution should be taken when matching colors on shrink sleeves. High shrink
     areas of sleeve will cause a color to dramatically turn darker due to concentration
     of ink in that specific area. This is very noticeable when the same color of ink is
     located on label in both a high shrink and normal shrink location. Customer
     should be contacted to inform them of color change and seek their final approval
     prior to manufacturing of order. If customer cannot accept this color variation
     then the high shrink area color can be made from a screen (possibly 70-80%) to
     reduce the intensity of color in a specific area. Test should be performed to
     determine the exact screen value.

Bar/UPC Codes
     Bar/UPC codes should never run in the machine direction on shrink sleeve. If
     customer artwork displays codes running in machine direction request customer
     approve change to cross machine direction. If customer declines a change to cross
     machine direction then notify customer you will not be responsible for codes that
     will scan.

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