Corel: Introduction to Bitmaps for Dye Sublimation

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By Steve Spence I just finished recording a YouTube video for CondeTV about bitmaps. Working with bitmaps is perhaps the most difficult thing one has to learn when learning sublimation. They are confusing, highly varied as to quality and type and all in all, just a pain in the neck.   Yet, we obviously need to work with bitmaps and learn how to manipulate them to obtain our goals. To do this, it is vital that we have a clear understanding of what a bitmap is, how CorelDRAW deals with it; what CorelDRAW can and cannot do with a bitmap and how to fix things when everything goes wrong.   What is covered in the 20+ minute video can’t be spelled out in a short blog so I hope you will make the time to view the video but here is a quick overview:   In sublimation (and CorelDRAW), there are two types of art work: Bitmaps and vector drawings. Vector art is easy. It is usually clipart. It can be enlarged or reduced as much as you want without changing the quality of the image. You can reverse it, lay one piece over top of another, change the colors, remove parts of it, etc.   Bitmaps come into Corel as a single object. They can’t be enlarged like clipart because they bring with them a preset resolution. In sublimation, we want to work with images that are 300 dpi. Bitmaps from the Internet are usually 75 or 96 dpi – far too low to be of any value when printed. The confusing thing is they look so good on the screen.   We can usually reduce the size of a bitmap without much trouble but enlarging it is another thing. With the super sophisticated CorelDRAW, we can enlarge good quality images somewhat but eventually, they will fall apart and no matter how we enlarge a bitmap beyond 300 dpi, we are losing much needed quality.   Photos taken by a digital camera, scanner, movie camera, etc., are always bitmaps. In fact, ANY photograph, no matter how it is obtained, will be a bitmap and will come in with all the restraints bitmaps normally have. These can be VERY limiting as to what they allow us to do with them. In many cases, you can’t lay one image over another because of the dreaded “white bounding box” and although there are sometimes ways to work around these, more often than not, we are just stuck with them - unless you are willing to spend considerable time learning how to mask an image or invest in specialized software.   At the very least, all sublimators need to understand resolution and how to work with it. Likewise, it is important to know how to import bitmaps into Corel properly.   “Introduction to Bitmaps” was recorded to provide a simple explanation of what a sublimator needs to know when working with bitmaps. I hope you find it helpful.