What Is Laundry Sizing?

Laundry Sizing
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Definition of Laundry Sizing for Ironing

Sizing is a resinous solution that adds body to fabric, creates soil resistance and ease of soil removal in the wash and makes ironing easier. The solution can be vegetable or petroleum based. It is often applied by the textile manufacturer during weaving or knitting and by the clothing manufacturer during construction of garments. Some textile companies use formaldehyde as a fabric sizer which is another good reason to launder all new clothes before wearing.

Laundry sizing or fabric finishes are also available in aerosol and trigger spray bottles for home use. They can be purchased in most mass markets or online from Amazon.

Sizing is the preferred method of adding body and crispness to clothes made of man-made fibers such as polyester because vegetable-based starch will not adhere to these fibers. It can be used with the lower ironing temperatures recommended for these fabrics. Sizing can be used at higher temperatures when ironing natural fibers but is not as effective for adding stiffness as starch.

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Alternative Names Of Laundry Sizing

  • fabric finisher
  • light ironing spray

Laundry Sizing vs Laundry Starch

If you are looking for stiff collars and cuffs on a natural fiber fabric like cotton, linen or bamboo, use starch. Starch is made from wheat, corn or rice and can be mixed in concentrations that will completely stiffen natural fabrics.

If you want only a slight crispness and a smoother, sharper looked to any fabric - natural or man-made - after ironing, use sizing.

Sizing does not discolor fabrics and is safe to use on all washable fabrics. It is so light that scorching or gumming up an iron plate is less likely than with starch.

Spray sizing is removed from the fabric after each washing and should be reapplied at the time of each ironing.

How to Use Laundry Sizing for Ironing

While starch can be applied to fabrics and allowed to dry before ironing, you will have better results with sizing if you spray small areas of the garment just before ironing. Hold the sizing can or bottle about eight to ten inches away from the fabric and spray with a light even coating.

Iron the area following the recommended iron temperature setting for the fabric type. Then move to the next area. Allow the ironed garment to cool and dry completely before wearing or storing to avoid excessive wrinkling.

Other Uses Of The Term Sizing

  • A form of sizing is used during the manufacturing of paper to reduce liquid absorbency. The addition of sizing allows inks and paints to remain on the surface of the paper rather than being absorbed. This is particularly important when printing wallpaper, art and reading materials.
  • The term sizing is also used for any surface to which gilding or gold leaf will be added. Again, this sizing of the wood, plaster or paper allows the gold leaf to more quickly adhere to the desired surface.
  • In weaving, sizing the term for size thats applied to the warp yarn on a loom and is essential to reduce breakage by improving the strength and abrasion resistance of the yarn. Size can be made from starch, oil, wax, gelatin or manufactured polymers.