Two denominators, not one
Ask a shop what a screen costs and you usually get one number. There are two, and they behave differently enough that averaging them hides the thing worth knowing. Emulsion, chemicals, film, tape and the person doing the coating and the reclaiming are consumed on every cycle. The frame and the mesh are bought once and used until the tension or the ghosting finishes them, so their contribution to any single screen is the purchase price divided by how many reclaims it survives.
That difference decides where effort pays. If the recurring side dominates, buying better frames barely moves the number. If the frame dominates — which happens when mesh is being retired after a handful of reclaims — then everything about how frames are handled matters more than the price of emulsion.
Getting the emulsion film right
The volume arithmetic is straightforward: mesh area times film thickness times the number of coats. The film thickness is not. It depends on the scoop coater edge, the speed, the angle, the mesh, the emulsion solids and whether you are coating wet on wet or drying between. The only way to know yours is to weigh a screen before and after coating and divide by the area. This page does not supply a number, and any page that does is describing someone else's shop.
Where this stops
Exposure is not here. Nothing on this page states an exposure time, a light source, a step wedge reading, an emulsion over mesh ratio or a stencil thickness, because all of those belong to the emulsion data sheet and to a test on your own equipment. This calculator costs a screen; it does not tell you how to make one.
Related
The per-screen figure here is what belongs in the screen charge field of the setup and break-even calculator, where it becomes part of the lump that a run has to amortise. The ink side is in the ink coverage calculator. For a general consumable bought in containers and used per unit, see the craft material cost per unit calculator.
Questions people ask
Should the labour figure include drying time?
Only the part where somebody is doing something. A screen sitting in a drying cabinet costs you cabinet space and calendar time, not wages, so it does not belong in a minutes-per-screen field multiplied by an hourly rate. Where drying does cost money is in how many frames you have to own to keep the press fed, and that shows up in this calculation as the frame line rather than the labour line.
How do I know how many reclaims a mesh survives?
From your own scrap pile. Count the screens you rescreened in a year and divide the frames in service by that, or track a batch of new screens and see how many cycles they do before the tension or the ghosting retires them. The number varies enormously with how aggressive the reclaiming is and what the mesh count is, which is why it is a field. If you genuinely have no idea, run the calculator at two values and see how much it changes the answer.
Why is the frame cost divided by reclaims rather than by jobs?
Because a reclaim is what wears the mesh, and one coating usually serves one job. If you print a repeat order off a coating you never washed out, the frame and the emulsion both stretch over more jobs and the per-job cost drops. The calculator deliberately costs one coating cycle, which is the unit that repeats.
What if I do not reclaim at all and buy new screens each time?
Set the reclaim count to 1. The frame line becomes the full frame price and, on most inputs, immediately becomes the largest number on the page. The calculator will say so. That is a legitimate way to run a shop for very small volumes, but it makes the screen charge in your quoting arithmetic much larger, which is exactly the effect worth seeing before you decide.
Does coating both sides really double the emulsion?
It multiplies by the total number of coats, whichever side they are on, because the arithmetic is film thickness times passes over the same area. Two on the print side and one on the squeegee side is three coats of volume. Whether that stack is the right stencil for your mesh and your run length is a separate question and one for a test, not a formula.