rasterice for screenprint

[wilmboom]

Hallo,

 

i try to rasterise a black and white picture for screen print but i can only set the size of the dot

whiteout knowing what measurement id used.

I would like to set the size in lines per inch or centimeters, is that also possible?

Greatings Willem Boom

[Komatös]

Hello @wilmboom and welcome to the forums.

Have a look.

[R C-R]

1 hour ago, Komatös said:

Have a look.

Maybe it is different on Windows but on Macs a right-click opens the document units menu. also, in AP's Document window, if you choose Resize Document, you can change the document units there as well.

[Komatös]

1 minute ago, R C-R said:

Maybe it is different on Windows

No, it's the same on Winows. I don't know why I had mixed up left and right. 🤔

[wilmboom]

Thanks for these answers but when i go to the live filters and click halftone

i can change the cell size (i think the dots) but wat is it pica mm ??

And can i somewhere get to the lines per inch or cm?

 

[R C-R]

33 minutes ago, wilmboom said:

... but wat is it pica mm ??

If you mean Pica (without the mm) it is a typographical unit of measurement of about 1/6 of an inch or 4.2 mm.

[wilmboom]

yes but it doesn't say wat it is this cell size,

but what i really want is to have it rasterise in lines per inch or centimeters.

[PaulEC]

I don’t think you can set measurement units, it’s just a scale from 2 to 500.

[Oufti]

I don't think Affinity is the most adequate program to prepare clichés for screen printing:

• Its halftone live filter is only a simulation of an halftone screen, even using some anti-aliasing!
• There are some artefacts along the edges of shapes
• Affinity doesn't know about 1 bit color documents, thus it's always converted to grays or RGB. It's not an easy thing to keep pure black in CMYK, and Affinity doesn't offer you a means to check if that's correct. 
• Finally, Affinity ignores lpi, they don't even distinguish between 'pixels per inch' and 'dots per inch'… Thus, to speak about lines per inch… 

 

12 hours ago, wilmboom said:

when i go to the live filters and click halftone

i can change the cell size (i think the dots) but wat is it [?] pica mm ??

And can i somewhere get to the lines per inch or cm?

For the rest, it appears the cell size, as expressed in the dialog, is somewhat related to the resolution of the document (in pixels per inch, erroneously shown as 'dpi' by Affinity). I would say that:

Cell size = ppi * in

In this example: cell size 30 / 300 ppi = 0,1 inch

 

 

On another: Cell size 36 = 0,5 in * 72 ppi

 

I conclude that the cell size is expressed in pixels (like many things inside Affinity, it seems to me). 

To calculate the screen ruling (lpi or lpcm, shown here by the oblique grid), you could divide the document resolution (in ppi, said to be dpi) by the cell size.

 

 

[wilmboom]

Thanks, i wil try your suggestion and if it gets to complicated,

i wil find someway with adobe photoshop to fix it, but thanks for your 

explenation anyway 

Willem Boom