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File size reduction list

• Merge layers in native Photoshop files (.PSD).
• Delete any alpha channels that are no longer needed.
• Reduce the resolution or the physical size of the image
• Reduce the number of colours in the image palette.
• Use a format that compresses the file.

Reducing the resolution is not a good idea if you’re going to print the image, but can be reduced to 250 – 300 DPI if the picture is going to be printed on fabric, as this is generally beyond the capability of the printer, but give the best results.

Using a compressed format means choosing a file format, such as TIFF with LZW compression, that automatically shrinks the file down as small as possible when it saves. In the case of TIFF, Photoshop does this by a means called lossless compression, so there’s no image degradation or blotchy colour. LZW compression (named for its inventors, Lempel, Ziv, and Welch) is also used by GIF and PDF formats.

With that many formats to choose from, it’s hard to decide which one to use?

It’s really not so difficult. As long as you are working on an image, keep saving it as a Photoshop document (.psd) as this makes sense, especially working in layers, because Photoshop can save the layers, whereas most other formats (Jpeg, BMP etc) require that you merge the layers into one so after you have flattened the layers, you can’t split them apart again.

NOTE: TIFF’s CANNOT bring transparency through into Adobe Illustrator. If you need transparency in imagery, user PSD files.

Just remember to be aware of what the imagery inside Photoshop is going to be used for, so that you can best choose how big the file needs to be in real life, so that you only save ONE file for use inside Illustrator & Photoshop and this same file can be sent to the factory. The example above was 21MB and we reduced it down to 5MB (Over 75% reduction in size) which will obviously take a lot less time to send over the internet to suppliers.

Adobe PDF Files

When saving artwork from Illustrator to send this to either a supplier or customer, it is advisable that you send the file as a PDF.

There are TWO options that you need to be aware of when saving in this format:

1. 1.       Illustrator Default – (Use this for In-House and to edit all data inside Illustrator)

• These are the default settings when saving an Illustrator file as an Adobe PDF document. Use these settings when you plan on editing the file again in Illustrator, or when you need to place it in a layout application such as InDesign, or when the final use of the file is unknown.

 

1. 2.       Smallest file Size – ( Use this when you are sending data to suppliers/customers for approval)

• These are the default settings when saving an Illustrator file as an Adobe PDF document. Use these settings when you plan on editing the file again in Illustrator, or when you need to place it in a layout application such as InDesign, or when the final use of the file is unknown.

It is not ALWAYS right to use PDF as a file format, but it is important to note that PDF files will keep VECTOR data such garment outlines etc generally intact, and convert imagery into JPEG format as it sees fit. You should get better quality imagery with a comparable file size using PDF.

Vector Graphics and Adobe Illustrator CS/2/3:

For vector graphics, a lot of customers prefer to us the EPS file format or alternatively PDF as these are NON Illustrator specific files.

If you save as an .AI file, then this will only work in Adobe illustrator and Adobe Photoshop. If you save as an EPS file, you can open this in a multitude of other applications that are not Adobe specific.

If you are sending artwork to a customer you can from Illustrator save the file as a PDF with the compression set to Smallest File Size.

“Illustrator Default”: These are the default settings when saving an Illustrator file as an Adobe PDF document. Use these settings when you plan on editing the file again in Illustrator, or when you need to place it in a layout application such as InDesign, or when the final use of the file is unknown.

“Smallest File Size”: Use these settings to create Adobe PDF documents best suited for on-screen display, e-mail, and the Internet.  Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.

Comparison of file sizes:

 

Scans and Pictures, Raster Graphics, Adobe Photoshop CS/2/3

For Raster and bitmap Formats, start with TIFF LZW or stick to a native PSD file for reworking designs in Photoshop.

Tiff LZW is a compressed file, so stays small on disk. Unlike Jpeg files there is no loss of image quality so always remember, Zip and LZW when saving as a Tiff file. Tiff files are simple files but still enable you to contain layers so all information is kept in the file for rework if needed.

Jpeg is not a good format to save in, as once a  jpeg is saved, that file has been degraded to whatever level of compression has been used. If you ever need to edit that image or modify that file again, EVER, do not use Jpeg. It is really important to know what Jpeg’s do and  to ONLY use it on final files to never be edited again – sending out to a customer etc to show what a design looks like.

 

.EPS file Type:

There are two distinct types of .EPS files, one of which is a “vector graphics file” and can be opened and easily edited for type, colour, etc. in vector based programs like Adobe Illustrator or Corel Draw etc. They can be almost infinitely scaled in size without degrading the output because they are vector.

The other is an .EPS “image file”, flattened, set resolution “raster”. It can be opened in Photoshop or other image editing programs, but it will be significantly degraded if scaled beyond the set resolution.

.EPS is the extension for an ‘Encapsulated PostScript’ file, which is a PostScript document made for use as a graphics file format. In other words, EPS files are more-or-less self-contained, reasonably predictable PostScript documents that describe an image or drawing (aka raster or vector), that can be placed within another PostScript document.

.AI file Type:

Vector image file created by Adobe Illustrator; composed of paths, or lines connected by points, instead of bitmap data; may include objects, colour, and text; often referred to as an Illustrator drawing. Illustrator documents can be opened with Photoshop, but the image will be rasterized, meaning it will be converted from a vector image to a bitmap.

.PDF file Type:

Cross-platform document created by Adobe Acrobat or a program with the Acrobat plug-in; commonly used for e-mail attachments or for saving publications in a standard format for viewing on multiple computers; usually created from another document instead of from scratch.

May contain text, images, forms, annotations, outlines, and other data; preserves fonts and formatting electronically across multiple platforms; appears on the screen as it will when printed on paper. Google and other search engines now index PDF documents, which can be viewed in a Web browser using the free Adobe Reader plug-in.

.PS file Type:

Document created by Adobe Photoshop, the most commonly used professional image editing program; can include image layers, adjustment layers, layer masks, annotation notes, file information, keywords, and other Photoshop-specific elements. Supports RGB, CMYK, greyscale, monochrome, duotone, indexed colour, Lab colour, and multichannel colour modes.

.Tiff file Type:

High-quality graphics format that supports colour depths from 1 to 24-bit; designed to be a standard image format for storing high-quality colour images on multiple computer platforms; may contain multiple layers and pages.

.Png file Type:

Image format that uses indexed colours and lossless compression (like a .GIF file), but without copyright limitations; cannot be animated like a GIF image, though the related .MNG format can. PNG images may also include an 8-bit transparency channel, which allows the colours in the image to fade from opaque to transparent; GIF images only support fully opaque or fully transparent pixels; PNG images are now supported by most Web browsers.

.Jpeg / .Jpg file Type:

Compressed graphic format standardised by the JPEG (Joint Photographic Experts Group) group; commonly used for storing digital photos since the format supports up to 24-bit colour; also a common format for publishing Web graphics; compressed using Lossy compression (Lossy file compression results in lost data and quality from the original version), which may noticeably reduce the image quality if a high amount of compression is used.

.Gif file Type:

Image file that may contain up to 256 indexed colours; colour palette may be a predefined set of colours or may be adapted to the colours in the image; lossless format, meaning the clarity of the image is not compromised with GIF compression.

GIFs are common format for Web graphics, especially small images and images that contain text, such as navigation buttons; however, JPEG (.JPG) images are better for showing photos because they are not limited in the number of colours they can display.

GIF images can also be animated and saved as “animated GIFs,” which are often used to display basic animations on websites; they may also include transparent pixels, which allow them to blend with different colour backgrounds; however, pixels in a GIF image must be either fully transparent or fully opaque, so the transparency cannot be faded like a .PNG image.