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GT-782 Cookbook: Troubleshooting 2
White lines are sticking out!





********* Erase Anti-alias or Align the Print Heads *********


You will already have your actual print image in your mind before you start printing. After you print, maybe sometimes you'll have to sigh, saying "Printer worked well, but that's not what I want!" The main reasons to make print worse are two: roughess and dullness of artwork and the differences of colors between monitor and printer. Let us explain the former issue: the latter, refer to TIPS of Color Matching.

The main complaints would be:
Why the artwork has lots of white brims all around?
Why the artwork is dull and vague, or even it is not smooth nor solid?

Maybe the original artwork (image data) might be too small and/or in low resolution. Before talking about the resolution, think about the digital image format.

Computer graphics falls into two main categories: Vector objects (images) and Bitmap images. With basic concepts, how your artwork is made, you will control your print quality easier.

Vector objects are made of lines and curves called vectors, using bezier curves, this is a story of math. You can draw vector data with CorelDRAW or Illustrator, or even PowerPoint. Vectors can resize and move without losing quality. In other words, vector graphics are resolution-independent. Also the size of vector images is comparatively small.

Bitmap images, sometimes called raster images, use numbers of a small grid of colors called pixels to represent images. When you zoom up, Bitmap images are like mosaic work with jagged edges. An image is made with lots of small squares (bitmap). You can make bitmap data with Photoshop or Paint Shop, or Paint. Bitmap images are most common --- images from scanners and digital cameras, digital paintings.

What is the most important is:

Resolution desides the size of each bitmap square.

Your customers will bring artwork images in Bitmap images rather than Vector graphics, because .bmp, .jpg, .tif are application-free. But don't forget that they are resolution-dependent.

When the resolution is higher, the size of bitmap square is smaller. This means the number of pixels (grids or dots) in an inch is larger to represent the fine and smooth details of the image.
Compare the images below: you can now tell which is which.
The left heart is only 6 x 6ppi(pixel per inch) when the outer square is one inch. The right heart is 18 x 18ppi.

Surely higher resolution is better, but you'd better think about the file size!

As explained above, Bitmap images are resolution-dependent. If you enlarge the Bitmap image without changing resolutions, this means you simply enlarge the size of each pixel. See the three hearts below; the center heart is the original, the left one is Vector graphics and the right one is Bitmap images. Both hearts are trebled. Be careful, the right one is no more a heart, it is shaken and broken...

enlarged vectororiginalenlarged bitmap


Let's go back to the issue of white brims. See the following images and guess what are the difference between vector and bitmap.

vector artwork on white backgroundprint image by GT File Viewer


no-compressed 150 dpi jpg imageprint image by GT File Viewer

Bitmap data sometimes cause additional troubles: compression level.

high-compressed 150 dpi jpg imageprint image by GT File Viewer



So, what you have to care first? Well, do not believe the image quality just on PC monitor, check the resolution and pixel number of artwork. The resolution of PC monitor is only 72dpi(dot per inch, =ppi), sometimes 96dpi. GT-541 has 560 x 600dpi (printers use only dpi) with large drops of ink. Ordinal Inkjet printer and MFC (Multi Function Center of Brother) for office is 1200x1200dpi, 4800x1200dpi for photo-quality. When you want to print a photo image on T-shirt, the resolution should be 200dpi - 300dpi. If you use scanner, at least 300dpi is required. I recommend you to scan in 600dpi then resize down to 200 - 300dpi with Photoshop.

Anyway if your customer's photo is too small (low resolution), it might be better to offer him/her some digital effect, for example Filter, Gray scale, posterization etc. with CorelDRAW and Photoshop to make a new artistic image. If the artwork is clipart, then the resolution will be enough in around 100dpi.
Also pay attention if the Bitmap image has some effects like Anti-alias and Drop Shadow effect. These effects work sometimes good and sometimes bad for T-shirt artwork designs. (For more information, refer to Edit anti-alias), especially to the photo page.


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