Erasing in Corel Draw and its Back!!

[Bill George]

Don't get it? I have a converted 8 bit gray scale in X6 and some areas when erased with Eraser Tool keep re-appearing? Not all but its like they are being stored someplace and keep getting restored?
I have Reduce Nodes button clicked in the Property bar... what am I missing?

[Mike Null]

Bill

Why don't you try editing in PhotoPaint and save your work frequently. Not sure this is your answer but it's worth a try.

[Bill George]

Got it by trial and error. Took it back into Paint and used the Magic Wand to select areas and Delete and back into Draw and was able to Erase those areas? Anyway it worked. Thanks for the reply. BTW I always Save about every 5 minutes or so, had a crash yesterday with X6 running on Win 7 Pro 64 bit. Glad I had Saved.

[Dan Hintz]

I'm confused... nodes are a vector item, but you're talking about removing part of a bitmap...

[Mike Null]

Dan

When you use the eraser tool on a bitmap in CorelDraw node like objects appear on the drawing. They are visible and can be deleted or moved with the shape tool.

eraser_nodes_001.png

[Dan Hintz]

Ah, gotcha... don't really use the bitmap tools in Corel (I find the free tools to be more useful and user-friendly).

[Bill Stearns]

DAN
Maybe this is 'good time 'n place for me to ask: When engraving photographs/graphics (wood or granite) I believe you've suggested using 1 Bit. (if I'm not mistaken?) Walk me thru this, if you will. Here's my current procedure. In Photoshop CS5 I get the photo/image 'way I want it - then, convert it to grayscale - 8 Bit (the 1 Bit button is there but doesn't light up.) Then I bring it into PhotoGrave for engraving. Should I first be converting the photo to "black 'n white" or something? - for the 1 bit button to show? And, would 1-bit give me a better engraving than 8 bit? (I understand dots per inch; guess I don't know 'bout "bits".) Eager to hear ...

Bill

[Dan Hintz]

DAN
Maybe this is 'good time 'n place for me to ask: When engraving photographs/graphics (wood or granite) I believe you've suggested using 1 Bit. (if I'm not mistaken?) Walk me thru this, if you will. Here's my current procedure. In Photoshop CS5 I get the photo/image 'way I want it - then, convert it to grayscale - 8 Bit (the 1 Bit button is there but doesn't light up.) Then I bring it into PhotoGrave for engraving. Should I first be converting the photo to "black 'n white" or something? - for the 1 bit button to show? And, would 1-bit give me a better engraving than 8 bit? (I understand dots per inch; guess I don't know 'bout "bits".) Eager to hear ...

Bill

Depends upon the substrate, Bill... if it's a 1-bit substrate (like glass), then a 1-bit image is what you want to work with (or have the laser control software convert to automatically). If it's a greater-than-1-bit substrate (as wood can be), then using the laser's "3D mode" is more appropriate (though you have to set up the various levels of power for the substrate you're working with).

[Bill George]

With my very limited experience with Photograv, it does not seem to care if its color, grayscale or whatever as long as its a BMP which seems to work better. It changes it to grayscale and allows you to make image changes with a on screen preview side by side with the OEM file. When I Final Process and go to Save the ENG file I always select BMP for the file that I use for the laser Import and with the SIM preview image I Save in JPG.

What I found out today, I imported a grayscale BMP image into Corel after I had did the type setting on a project. Arranged all, and sent to PG as a BMP which took the file and just processed the image along with the text and all. It turned out very nice.

[Bill Stearns]

DAN -
A "1 Bit substrate" ?? - (like glass?) - just when I think I know everything - new to me that substrates are gauged by "bits". What the heck is a "bit", anyhow? Don't think you explained that. ? - Would you please get back to work on your book!

Bill

[David Somers]

Ah.....this is easy Bill. I got this question Dan!!!

When you have a 1 bit substrate it simply means you were able to buy 1/8 of a US Dollars worth of the material from the vendor. S&H and taxes are more of course. A 2 bit substrate is a quarters worth. We are all familiar with the term two bits I believe? And an 8 bit substrate would be an entire dollars worth of it.

And....if you ask a vendor for 1 bits worth of a substrate he may tell you to "get real!" That is not his way of saying "you have got to be kidding!" He is telling you the minimum purchase for that substrate is the old Spanish Real or the old Spanish Dollar. Be suspicious of this vendor at this point since he is trying to get you to buy your substrate with a valuable old world coin. Make sure you get enough pieces of eight or Reales in change and don't forget about the exchange rate.

There. Doesn't that help?

Dave

[Bill George]

So can you pay with Bitcoin?

[Dan Hintz]

To expand on David's answer.. you don't want the 1-pound substrates. Gets expensive fast.




A "1-bit" substrate (like glass) would be something that is either marked or unmarked. When you hit a piece of glass with a low-power laser, there is no mark... as you increase the power, at some point it's strong enough to make the glass fracture at that point (we'll call that marked). There's no in-between area, it's either marked or it isn't, fractured or not fractured.

A "multi-bit" substrate (like wood) would be something that can have multiple levels of marking. I could have a very light burn, or I could have a dark, sooty burn, and many levels of burn in-between.

1-bit substrates require you to simulate a picture by varying the space between these marks/dots (a form of halftoning)... note, these dots are all the same size. This would be a 1-bit image that comes out of programs like PhotoGrav. A multi-bit substrate lets you vary the darkness of those marks/dots by changing the strength of the laser pulse (higher power generally leads to a darker mark), but the spacing between them stays the same. This works well with greater-than-1-bit images, such as an 8-bit BMP, as long as you have provided a good mapping between darkness of a pixel in the original image and the power level of each pulse.

Clear?